My co-worker went that route on his s10. Bought regular auto primer, paint, and reducer, and an hvlp gun set. Once he figured out the proper settings on the gun to get a good coat, he'd already painted the entire truck and sanded it all off (because it looked like crap) 3 times. He finally got a good smooth coat of paint on it, but the clear coat is dull, almost like it's not even there. He did finally figure out the problem, but he's not going thru the hassle of sanding the truck and repainting it again. His total investment so far, not counting the guns, is about $400. That's why I'm going to try the roller method on my truck. I can't afford $400 for a do it myself paint job.