Found a great glitch, it makes you invincible as long as you're inside of a vehicle. First, walk up to a vehicle, (Must be destroyed) and prone next to it. Now, prone into it while walking, and press up and down on directional pad over and over as you're walking. Soon, you should be under a vehicle. You can stand up in any that aren't on fire, it's pretty useful. If you want to get inside tanks easier, go in the back of it, and try the glitch, into the treads. It's easier.
Added by: The Ironhide Oct 19th 2008, ID#31077