To get every upgrade for the DeSoto you need to complete driving minigames that appear in Episodes 1, 2, 3, and 5. The minigame is started by talking to the C.O.P.S. in the garage, which is the furthest right building on Straight Street.
To claim the upgrades you need to complete each minigame in three rounds of increasing difficulty and also drive over or shoot some special items that appear in the stages. Here is a checklist and short description of what you will need to do:
- redjarman has a good tip in the comments. After you get each decal, be sure to save the game manually - do not rely on the autosave. When you have all the decals in a Chapter be sure to manually save again.
- Drive over 40 Torture Me Elmers in 60 seconds
- Drive over 50 Torture Me Elmers in 60 seconds
- Drive over 60 Torture Me Elmers in 60 seconds
- Drive over the 10 Bowling Pins in the middle of the road (you need to knock them all down)
- Drive into the Red Cheese Wheel that rolls across the street from the left side
- Shoot the piano hanging from a window on the right side
- Shoot the Good Tire Blimp flying across the top of the screen starting on the left
Reward: Turbo Charger
Tips: Stick to the right side of the road as I have found that there are more Elmers there, but avoid the yellow ramps since jumping will simply waste time. It took a while for the blimp to appear in my game (4-5 minutes), so if it doesn't appear for you right away be patient.
- Complete Bagpipe Obliteration Ultimate in Bronze Difficulty
- Complete Bagpipe Obliteration Ultimate in Silver Difficulty
- Complete Bagpipe Obliteration Ultimate in Gold Difficulty
- Shoot the Hot Air Balloon flying in the sky from the left
- Shoot the Safe hanging from a window on the left
- Drive into (or shoot) the Huge Tire rolling across the street from the left
- Shoot the Kitchen Sink that is thrown from the right (just keep hitting A to fire...it may take a couple tries)
Reward: Dashboard Hula Girl
Tips: The Bagpipe Obliteration game on Gold level is the hardest decal to obtain in the game. You need to drive over the bagpipes and avoid the accordians that are often placed right in front of them. Hit too many accordians and/or miss too many bagpipes and you will lose. The best advice I can give is to practice sideswiping the bagpipes so you barely graze them but still run over them. If you attempt to run over the bagpipes head on while playing the higher levels you will make things much more difficult on yourself.
- Hit 15 zombies with SOL discs
- Hit 20 zombies with SOL discs
- Hit 25 zombies with SOL discs
- Run over (or shoot) the Beach Ball that bounces across the road from the left
- Run over the Beer Keg on the left side pavement
- Run over the Box Kite in the middle of the road
- Run over the Satellite Dish on the right side pavement
Reward: Flame paint job for DeSoto
Tips: An easy episode once you get the timing of throwing the discs down...if you've played Paperboy before it plays similarly.
- Shoot 25 Evil Rats in 60 seconds
- Shoot 35 Evil Rats in 60 seconds
- Shoot 45 Evil Rats in 60 seconds
- Shoot the Huge Rubber Duck that appears on the left side
- Shoot the Flying Car that flies over the middle of the road
- Shoot the Soccer Ball that bounces across the road from the right side
- Run over (or shoot) the Doughnut that rolls across the road from the right.
Reward: Demonic Grill Teeth
Super Upgrade: Police Lights on the DeSoto (if all others collected)
Tips: When shooting the rats, try to always be ahead of the game and shooting the ones farther down the road - if you wait till they get too close to the car it will be harder to keep up. Don't be afraid to constantly fire as you have no ammo restrictions.
If you do these out of order just go back to Episode 5 once you have all the upgrades and go to the C.O.P.S. in the garage. Choose to try their game again and once it starts just choose to go back to Straight Street and you will get the final upgrade and the achievement.