For those of you who, like me, prefer text -
All credit goes to Teh Paralyzer for his solution on xbox360achievements.org.
1. "Iacon Under Seige". When you come out of the briefing area after talking to Jetfire you will see a group of Autobots that get blasted, only one survives and you revive him. Pretty hard to miss.
2. "The Broken Lift". When you are coming out after you see the Decepticon War Machine you will see the hole in the wall. Instead of going left like your supposed to, go right and go around the loop until you see a lone Autobot who then gets shot down and you have to revive him.
3. "Road to Decagon". The third Autobot is where you first see the snipers. There are three Autobots out in the open and two get killed while the other gets downed. Hard to miss.
4. "Iacon Speedway". This is in the area after you talk to Ironhide about clearing the road. There is a Decepticon War Machine that already has its core exposed and when you look to the right you will see an Autobot that gets downed by is ray.
5. "Central Ventilation System". This is one of the trickiest. When you get to the area where you have to jump on the circling platforms you get to the area where Megatron is giving his speech you have to look to your right before you jump on the platforms. You will see a small cliff edging out of the environment. Jump on it and use the boost to get to a platform half-way, then jump the the large non-moving platform. You will be annoyed by some jets here but you can choose to not shoot them down. As long as you get to the next platform fast and wait for it to get half way, you will see the Autobot on a cliff next to the platforms. You have to double jump and boost to just make it and revive him. Hard to miss even harder to get.