Just finished this for a guy in Florida, pretty neat truck he has and I tried to match it the best I could. I used mat black and real rust for the under carriage and several colors under red primer for the body. Then I wet sanded the worn areas and shot some lusterless clear over that. The white walls are white primer sprayed with a template I made and the wheels are from (are very own) Forward Resin.
I did use a little salt in the bed to get a more beaten look. And the pinstripe and lettering was done by hand!