Question for the pro's

I have a car I painted about 5 years ago and want to simply change topcoat color. I did my usual steps of epoxy primer, sanding primer, epoxy with reducer as a sealer, and finally acrylic urethane topoat.
Question is after I scuff the car, is it necessary to put down a coat of epoxy primer, with or without reducer? I do plan to do a coat of high solid urethane primer to block, then top coat of acrylic urethane. I have always used the epoxy as a sealer but I probably get to involved with it all!???
This is a driver, but I know I can get TOO much material on the car.