Note: This procedure requires editing a game file; creating a backup copy of the file before proceeding is recommended. With a text editor, edit one of the vehicle configuration file named "*.cfg" in the "\Infogrames Interactive\Deadly Dozen\GameData\Vehicles" folder. Look for "body_armor", and set it to 9900.0 (this may create some smoke effects, but it is not a problem). Look for "troop_protection" value and set it to "300.00" (default is 90.0). Begin the game, use that vehicle, and drive around, Let enemy soldiers shoot at you. That driver's health will increase when getting hit, over 100. If it gets to over 500 or more, some enemies will not be able to detect you, even if you get close. You can also drive around and crash into enemies.