Was just looking over SEM website and they say for the satin trim paint "To promote adhesion on ABS, PVC and other similar
plastics, apply a medium wet coat of 38363 SAND FREE. Apply color while 38363 is still wet. As the 38363 evaporates, the color is drawn into the surface creating excellent adhesion. To promote adhesion on TPO, EPDM, PP and other similar thermoplastics, use 39863 PLASTIC ADHESION PROMOTER or 77723 XXX ADHESION PROMOTER." and not to use primer. I assume on metal - mirrors, bumper brackets, lower grille I made from aluminum should still get a primer, I reckon theirs? I can get it all quickly from year one if they have it in stock cause I am only 45 minutes away so truck shipping is still quick.