been invovled in auto painting since about 1978 been thru the ringer with all of the dupoint and PPG and sherwin williams auto colors
i prefer the ppg and teh sherwin in the polyurethanes base coat clear coat systems
also u can base coat it then apply ur decals before clearing and the decals stay better go to the local paint supply for auto and tell them what u want and what there prefered primer would be as there are sevreal to choose from depending on application
hopes this helps
glenn