I am planning on repainting my truck the same color as it currently is. There is a second coat over the original coat that is chipped and flaking in spots and it's a shade off from the original. I have painted a set of half doors Freeborn red with spray cans from Tower. They came out great, but they don't match the rest of the truck. Last year I stripped and repainted the bib and it doesn't match. So, do I need to strip of the top coat or can I just sand it and paint? Also, I assume I need to prime first?