Regarding the Mega Trainer 1.1, Kill Mission Timers, Infinite Stock....
Ok... To do this glitch you need the v1.1 Mega Trainer, a Maracaibo Bridge (the small bridges that cross over the main street, upon entry into Maracaibo), and a Tank (Any Tank, but the Diplomat Heavy Tank has the best climbing ability).
Now, activate the trainer, then activate Unlimited Vehicle Armor (4, on Numpad).
Then, drop, hijack, or commandeer a tank, drive to Maracaibo, and get under the small overpasses (the small streets that pass over the main street in Maracaibo).
Now, this only works 50/50, but blow the bridge with your tank shells, the bridge will fall on top of you, and you'll blow up (you'll either get forced out of the tank, which means it's dead, or you'll stay in, which means it's still alive).
If you're still in the tank, you can drive around headless, with no turret, though, the graphics/VFX of the tank will still be in the same position, as in, the projectile will still come out as though it hasn't lost it's barrel.
But, if you were forced out of the tank, repeat steps until you get desired effect. If you have run out of bridges to blow, reload the savegame, start all over. :-\