Oh, look, they found one of my team's practice videos.
Seriously, thought, that's awesome. Sadly, insurance regulations on any large game say that the driver compartments of paintballing vehicles need to be completely covered in either metal or paintball netting. Gunners don't, but, having played gunner in a 4000-man paintball game, you really, REALLY want to have some cover (Since any player NOT carrying an AT gun will immediately shoot the hell out of any exposed gunners so they can't shoot, at at least with any accuracy)
Still, you can find some pretty cool rigs rolling around, even with those rules.