priming plastic panels

ok heres what ive done so far to my plastic door panel pieces 1) washed them in hot water with a mild degreaser and soap 2)sanded them with 150 grit sandpaper(to smooth out the grain) 3)sprayed them with bulldog adhesion promoter 4)primed them (5 coats) 5)sanded them with 320 6)wet sanded them with 400 then I noticed this crack in the primer so I started diggin around at it and the primer didnt adhere in this certain area. I peeled the primer off very easily about 6" around one area with the crack the rest of the panel seemed like it adhered very nicely. does anyone know why this would happen? the only thought I can come up with is to much primer in that area please help!!!!-A vision without a plan is just a hallucination-

um im not a paint expert but i have done a lot of painting.   but it sounds like they werent quite clean...after sanding be sure to clean off your sanding debris, and after using any cleaners rinse well with water because even a little cleaner/degreaser will leave your paint volitile.. also try painting on the driest and hottest day possible and let them bake in sunBen carnes-2ma hk15x2 + 5500d

they were cleaned very well and dried properly,they were waxed and greased twice,I believe it was because i put too much primer on . I live in the high desert in oregon it was 98 degrees outside when i painted them thanks for the input but i was looking for someone who is a painter or custom fabricator , I do auto body and paint for a living but plastic is a whole new universe.-A vision without a plan is just a hallucination-