we have a local painter here, he does 10-20K amazing paint jobs in a 2 car garage. his trick is to keep the dirt down. he gets the car to its final stage ready to shoot, he lines the walls, ceiling, and floor, with clear visqueen plastic. makes a fresh bubble dirt free cell, rolls the car in, wipes the car down with a tac cloth and sprays away. with a single fan in the window to exhaust the fumes out.