I used a eBay fender on my Acura TL and just sanded and painted it. Came out good but a few months later I blew a chunk of paint off with a pressure washer even though I took every step or preparing the fender properly before paint. Paint/primer have 'pores' that close up after XX amount of hours dry time depending upon product. Spraying your paint over primer that is still in the 'recoatable' timeframe stated on the product data sheet will help ensure the two bond together chemically and physically to prevent the above scenario or premature deterioration. Who knows how long ago i or what kind of garbage primer they used so I've always felt It's worth the little extra prep and $$ to get much better results.
"I love deadlines- I like the whooshing sound they make as they fly by"
