[BigD9146gt]

914gt has the good call, keep your ground close to the work area. As for the battery, just dissconnect the ground. The only reason your buddies M3 was fried was because they probably didn't unhook the battery, and left the ground far away from the working spot.

You can always weld on a small tab to your flat work peice (like a new homemade floor pan) while you weld, then grind off the tab when your done. Any local relays or electrical equipment (withen 1 foot) can be removed for safety, but not too critical. It sounds like your buddies roll bar was done by a complete retard who knows nothing about auto body.