Bulldog, 3M and Duplicolor make adhesion promoters. Follow directions in this PDF.@magnetman you mention an adhesion promotor for plastics. Any more specific recommendation, brand/type etc? Looking to do the top of a roof top tent (ABS plastic hardshell) because I've had good success doing the roof of my 80. I think there will be other benefits to coating the rooftop tent hardshell (sound deadening, UV Protection, and durability from things scratching it).
ABS does fairly well with adhesion promo compared to other plastics