Here’s what I do to prep. Clean, clean Clean. I wash everything with dawn. Get it good and clean. I then go over everything with a tak cloth. Then I use commercial grade grease and wax remover. Not the cheap stuff in the spray can, professional grade you get in a automotive paint store. When using that stuff use gloves, read the warning label. I then tak again. If I know Armorall was used on the Vynal use go over it again with grease and wax followed with a tak cloth wipe down.

When ready to dye make sure the panel is warm. Allows the pores of the material to open up. I use SEM. Never used their prep spray. Using the method I described I’ve never had a problem with fisheyes. Word of caution, scuffs in plastic panels found on later cars should be scuffed with a red pad. In particular kick panels.