For thos who don't prefer a list, here it is. All credit goes to gamefront.com:
chapter 1
1. In the hallways of the BK building, instead of turning left, follow the elevators forward down the hall. On the left wall, near the window, you’ll find the first Golden PT92 pistol part.
2. Step out of the elevator into the lobby. Fight through the bad guys, and look right between two columns and a planter. You’ll find another Golden PT92 part.
3. In the parking garage, instead of turning left and chasing the bad guys, look on the back right corner for the last Golden PT92 part.
chapter 2
1. In the main club area, after jumping through the windows, kill all the gang bangers. Once the room is clear, turn around and climb up into the DJ booth to find a hidden Golden .38 Revolver part.
2. Run back upstairs in the same room, go into the VIP area and look behind the bar for a Golden Mini-30 part.
3. In the large purple-tinted bar and club area, where there are large windows on the right side of the room, follow the left wall up to a seating area. At the end of the seats is an Employees Only door, go through, down the short steps, and through another door to enter the DJ Booth with a Golden .38 Revolver part.
4. In the Asian themed restaurant, run into the central seating area and look behind the tables for a Golden Mini-30 part between the booths.
5. Run down from the helipad, but instead of continuing on into the roof, turn around the from stairs and look in the elevator lobby underneath the landing pad. Through the doors, look left to find the last Golden Mini-30 part.
6. On the catwalks below the massive red sign, run all the way to the end and turn right to find the last Golden .38 Revolver part.
chapter 3
1. Inside the Press room, enter the side filming room with the camera on the right wall. Inside, you’ll find the Golden M10 part.
2. In the sports store, look left of the counter and enter the side room. On the counter of shoes, find the Golden M82A1 Sniper Rifle part.
3. Outside, in the stands of the Stadium just outside the Sniper perch, turn around and run right down the steps to find a Golden M10 part at the bottom of the steps.
4. Down the curved VIP seats, follow the left wall to enter the first of the private seating rooms. On the floor of the front seats, you’ll find the last Golden M10 parts.
5. Back out into the stands, you’ll need to run back down the steps down to the bottom level. Turn left to find a set of gated exits to find another Golden M82A1 parts.
6. In the nosebleed seats leading to the last sniper position, stop at the last set of seats and turn right. Run down the path to the gate to find the last Golden M82A1 part.
chapter 4
1. In the bar, turn around and check right of the front door. On the floor, you’ll find a Golden 1911 part.
2. Find another Golden 1911 part at the back of the bar, up the stairs on the left side and all the way into the dead end.
3. Outside the bar, spying on the gang of goons standing near two cars, wipe out the gunmen then run back down the stairs. On the ground you’ll find the last Golden 1911 part there.
4. Back in Max’s apartment, turn around and look behind the couch to find a Golden M500 part.
5. In the blasted hallway, instead of running up the stairs, turn right to enter the destroyed apartment. On the floor, you can find a Golden SAF CAL part.
6. Stepping onto the roof, run around behind the roof access to find a Golden M500 part.
7. After falling off the Water Tower, climb up the wall to your left and continue running down that path. Ahead, you’ll find another inaccessible Roof Access, behind that you’ll find another Golden SAF CAL part.
8. Just as you use the steps to enter the second level of the dilapidated old building, turn left from the top of the stairs. Step around the metal poles and down a dead end alley to find a Golden M500 part.
9. Inside the chop shop, before leaving enter the office to the right. On the desk, find the last Golden SAF CAL part.
chapter 5
1. Exiting the warehouse and turn right, you’ll find stacks of shipping containers. Behind a fallen barrel, you can climb the brown wooden box wedged between the containers. Pull yourself up, and climb the container behind the box to find a Golden Micro 9MM part.
2. Leaving the garage and jumping down onto the overgrown streets, follow the right wall to a closed gate. Near the gate is another Golden 9MM part.
3. In the dock with the raised boat, follow the steps to the right up to the catwalk above. At the end of the catwalk, you’ll find the last Golden 9MM part.
4. Back inside another warehouse, you’ll find more shipping containers off the concrete landing. Take the steps down to find a cracking open container. Inside you can find a Golden .30 LMG part.
5. Outside, you’ll find a rickety shack with steps leading up inside on the waterfront. To the left of the shack is a small covered area with another Golden .30 LMG part.
6. On the boat docks, instead of running across the boat, turn left to continue on the concrete dock down to a gated dead end. Find the last of the Golden .30 LMG parts on the ground.
chapter 6
1. In the first office area with larger closed personal offices with glass walls to the left, enter the very first room. Behind the desk, you’ll find a Golden MD-97L part.
2. Taking a set of steps down into a seating area, turn right to find a waterfall. On the wood covering a narrow spillway, find another Golden MD-97L part.
3. After the car crash in the lobby, smash the glass case on the right open to find the last Golden MD-97L part.
Chapter 7
1. Inside the grungy bar, look inside the bathroom on the right. Check the center stall for a Golden Sawn-Off part.
2. Deeper into the favella, you’ll take some rusted steps down and enter an open structure, running through it. After leaving the first room, turn left to find another Golden Sawn-Off part on the ground near an electrical panel.
3. In an overgrown area, with thin beams of light streaming through the ceiling, you’ll enter a room with rusty stairs leading up into an optional area. Run to the top and look behind the barrels to find a Golden SPAS-15 part.
4. Back outside, down a large alley behind more buildings to your right and a wall to your left. Run past the burnt out car, and behind the rusty pallet on the right to find another Golden SPAS-15 part.
5. Running up a few steps of stone stairs through a narrow passage, you’ll stop on a small concrete landing overlooking the ground with a short fall. Drop off the right side to find the last Golden SPAS-15 part.
6. The last Golden Sawn-Off part can be found after a gun battle with gang members up a hill. Instead of running up the steps near a tree with enormous leaves hanging over the entrance, find the locked gate to the left for the part.
chapter 8
1. After getting rid of the Grenade Launcher goon on the large facade with two sets of stairs leading up, follow the road right to two mausoleums and a few gravestones. Behind the graves is a Golden AUTO 9mm part.
2. Fight through the incoming goons in white vans, and search behind a large circular planter to find a Golden 608 Bull part.
3. After leaving a building looking out onto a raised fountain, with covered areas to your left and right opened with multiple archways, turn right and look in the back corner before going up the stairs. You’ll find a Golden AUTO 9mm part.
4. Inside the large graveyard area with a gazebo at the center, run to the center gazebo and you’ll find a Golden 608 Bull part.
5. Before entering the Rest Home basement to your right, enter the shack to your left. In the small washroom, you can find a Golden Auto 9MM part.
6. Inside the Rest Home, inside the seating area where you’ll defend a small memorial against mob thugs, look underneath the podium for a Golden 608 Bull part.
Chapter 9
1. After fighting the Anti-Gang squad goons in a large vertical area with homes built with red bricks, you’ll need to run down concrete steps and into an alley. Just at the front of the alley, is a sunken home entrance. Enter the little sunken area to find a Golden DE .50 part.
2. Invading a woman’s home, she’ll scream and hide. Before you leave, check out her bathroom for a Golden M972 part.
3. Another M972 part can be found down the rainy alley, just near a set of stairs leading up to a rusty door.
4. In the grassy area with the metal fence, look for stacks of tires in the overgrowth to find another Golden DE .50 part.
5. At the very same area, leave the grass through a small path leading to another alley from a short fence. Instead of entering the alley, turn left and run towards the metal gate. Look left to find a Golden M972 part.
6. Reaching the wooden bridge where you’ll find more police thugs on the balcony across from you, cross the bridge and look for a rusty metal door. Open it and enter the small room to find a Golden DE .50 part.
Chapter 10
7. In the rusted mess of bus wrecks where the chapter begins, look for a roofless green bus in the middle of the arena. On the floor of the bus, you can find a Golden FAL part.
8. While fighting through one of the maintenance rooms, look for a small white closet filled with large containers on racks. There’s a Golden M4 Super 90 part on the floor inside.
9. Inside the large maintenance bay with the catwalks overhead, before running upstairs to meet up with your ally, explore the first floor. Behind the raised bus that can be lowered with a few shots to the control panel, look on the wall for a desk covered in tools. On the left side, you can find another Golden M4 Super 90 part.
10. Running down stairs into another garage with such a single green bus in the center, explore the bus. On one of the back seats you can find a Golden FAL part.
11. Entering the offices of the public transportation building, enter the back right large office and check the far corner for a Golden M4 Super 90 part.
12. From the same room, run down the stairs to continue and enter the small security office to find the final Golden FAL part.
Chapter 11
13. Inside the kitchen, run through the plastic strips and check the corner to Golden Super Sport part.
14. Back up on the dance floor, just outside where Max was enjoying a drink earlier, before you enter the bar look on the right side of the deck, down the narrow path to a dead end. There, you’ll find a Golden Super Sport part.
15. Inside a small open seating area inside, you’ll pass through an office with paintings flanking the door ahead. Run into the left painting to knock it off the wall, and a secret safe will open up to reveal a Golden AK-47 part.
16. Outside on the Panama Canal, after leaving the boat, you’ll need to press on toward the building ahead. Don’t, instead turn left and run behind the building, following a set of train tracks to a stopped train car. You’ll find another Golden AK-47 part on the ground.
17. Before entering the building with the “Bastid” murals, run to the right side of the railings to find a Golden Super Sport part.
18. To find the last Golden AK-47 part, after running up the stairs on the left side of the building, look for a smaller set of stairs to your right leading down. At the first set of stairs, run down to find the part.
Chapter 12
19. Inside a ruined bathroom near the start of the chapter, you’ll find a Golden RPG part.
20. Eventually you’ll reach a red room with a smashed wall on the right. Run down the hallway near the crumbled wall, and continue past the small crate to find a Golden FMP G35 part.
21. Down another red hallway, look for a smashed wall on your right leading into a bathroom. On the floor, pick up the Golden RPG part.
22. In the elevator lobby leading out onto the first roof, look behind the desk on the right side of the room to find a Golden FMP G35 part.
23. Entering a large room with red boarded up columns, look on the right side of the room for a small table and chair set up. Look behind the old chair for the last Golden FMP G35 part.
24. After fighting off snipers with a rifle of your own, back out of the balcony hotel room and turn right. Continue towards another balcony to find the last Golden RPG part.
Chapter 13
25. Escaping from your captor, don’t push deeper into the station yet. Instead, turn around and check out the prison cells behind, the same cells you were lead through in the cutscene. In the first one, you’ll find a Golden MPK part.
26. In the bloody hallway through the first room, look in the dark foggy room to your right as you traverse the halls. Inside, you’ll find a Golden LAW part.
27. Outside, after destroying the APC, run into the tunnel beneath. On the left side of the underground area, you’ll find a green dumpster. Behind the dumpster is a Golden LAW part.
28. On the street between the builds, and through a barbed-wire gate, you can find a Golden G6 Commando part.
29. Reaching the workout room, check inside the locker room shower to find a Golden MPK part.
30. Look inside the cafeteria, behind the serving counter in the kitchen to find a Golden G6 Commando part.
31. Down the main hallway of offices lined with planters, look inside one long office with a small projector and some fold-out seats. On the desk below the projector you can find the last Golden MPK part.
32. Across the office is a small security post. Behind the desk, you can find a Golden G6 Commando part.
33. At the shooting range, look to the left wall, behind the first pile of sandbags to find the last Golden LAW part.
Chapter 14
34. In the luggage sorting room, stand on the conveyor belt and follow it to it’s destination. It’ll lead you to a small cage, that you can climb onto to grab a Golden Rotary Grenade Launcher part.
35. On the catwalks above the luggage sorting room, run to an optional office with another set of double doors leading right. Enter those doors to find a Golden Rotary Grenade Launcher part on the floor ahead.
36. At the private airport offices, enter the double doors into the bathrooms / locker rooms. Find the last Golden Rotary Grenade Launcher part in the shower stall.
37. Inside the large airport concourse, take the escalator up to the second floor and cross the bridge to your left. Take another left to backtrack all the way to the corner to find a Golden RPD part.
38. Entering another concourse with seating areas to your left, follow the left wall until you can find a ticketing station with the Golden RPD part behind the desk.
39. After jumping out of your first train into the second train full of enemies, turn around and run to the back to find the last Golden RPD part.