[Curo]

Depends on the strength of the alloy and the density of the paint. On your average road car I.E a Chevy Blazer yea you should expect the paint to chip after the gloss clear coat and some minor dents from some of the closer range shots. My advice? Kremilin/Sames/Excel Paint offers a line of guns that they provide for the US Military to use when painting their M1 Tanks. These guns coupled with the correct paint create at a durable layer that is enough to deflect BB's. Infact it can deflect shrapanel from a hand grenade, with no cosmetic damage.

Problem is these guns cost almost as much as a beat up high mileage SUV off kijiji. The best idea IMO is get one of these beater SUV's and do with what you will but on game-day for milsims arrange a way to transport it to the field. Uhaul offers vehicles and trailers that are large enough to transport a smaller SUV. But a daily driver is not something you want to risk.

EDIT: I am talking about paint guns like the ones used to paint cars/boats not airsoft guns.