As 302/Z28 said, those cheapie window fans are induction motors without brushes, no sparks BUT there is when you turn it on & off in the switch! Be careful.
I've done some spray painting, mostly in indutrial applications for electrical cabinets, no too much automotive. 2 things I didn't see mentioned that I think are important to point out. Most modern automotive paints are toxic and can be absorbed through the skin. The other thing, GROUND EVERYTHING! otherwise if the car has a different charge, it'll attract particles in the air.