Punisher Bass
He who drives a Buick
Boric acid is a common thing to use to get rid of cockroaches and more effective than using cockroach baits.
Only you would suggest putting acid on a car. But considering your history with the subject of paint and bodywork, it shouldn't surprise me. Yes, brush large ammounts of an acid on your car and everything will be just fine, it won't cause any damage, nor could any other humans or animals be exposed to it.