In the Know Thy Enemy mission with jazz, how do you beat it? I can get the first vehicle but the i don't have enough health to get the second one.

That mission is actually pretty tough. I stuck to trying to stay on small building rooftops. it helps to block fire from ground vehicles better. and I jumped as I ran back to Optimus. Thats all I can help you with.

finished the game.

when you get the first one destroy the things in the junkyard to get life then on the secong one go through th mall then get life to battle the third vehicle

when you grab the second car, just go to the street and drop it by transforming, then drive away and get health by smashing things come back and destroy all the poliese cars and helicopters u can, sometimes u have to do it three or four times to get them all, but when you do u can just walk back to optimus prime with it undesturbed.