I'm on that last part in act 5(or 4) where I have to get past the boomers in 30 seconds to get to the tank. I've tried like 50 times with no luck. can anyone give me any pointers? I'm frustrated enough to use a cheat code- does this even exist?

Just run right past them dont shoot run, run, run!!

Just run right past them dont shoot run, run, run!!
Yup. Shoot the two boomers to start the clock, and run like Forrest Gump.

I got stuck here for what seemed like forever. I finally enlisted the help of my 10 year old nephew on co-op mode to get me through it. I just couldn't get it by myself.......even knowing I was just supposed to run like hell. When we did get through it, I found out that each time I died, I was about an inch from where I had to be to start the cut scene.

Yup. Shoot the two boomers to start the clock, and run like Forrest Gump.

run Forrest run!

got it finally! man that was rough

Co op is easier here since one person can stay behind and attract the attention of the boomers and the other can do the Forrest run for the vehicle. Only one person has to make it to trigger the end of the level.

I always have the torque bow at that stage of the game. So, I usually kill the first two boomers before the clock even starts. Then I run like hell.