I will point out that I am not doing this on a car right now, but on a metal screened structure for a porch and swimming pool. Anyhow, most of us have heard of the roller and brush then sand till you bleed method of painting a car with a $25 gallon of oil based Rustoleum. I tried it with a $15 Harbor Freight gravity feed gun and a 25 gallon, 4 hp Craftsman air compressor, and it comes out pretty good! As per the instructions on the can, I thinned it with Acetone and sprayed away. I am using white, and in doing a replacement screen door that was brown (I bought it used from Habitat for Humanity's Re-store) it took about 4 coats to get full coverage. It goes on smooth and would give a good finish with enough sanding and buffing, but would likely require 5 or 6 coats to give enough of a sanding base. Anyhow, I just thought I would throw this out there for anyone who was thinking about trying the roller and brush method. Also, you could try something like a Wagner power painter with this paint and probably get similar results.