I am getting ready to dye a set of door panels for my cuda (original black panels to burnt orange). I'm using the plastic and vinyl dye from Herb's. I've tried cleaning the panels multiple times as follows:

Dawn Dish Soap (Twice)
TSP (Twice)
Wax & Grease Remover
Acetone
Brake Cleaner (got frustrated)

After all this, the water still beads on the top of the panels (back of panels does not bead)so I know they are still not ready for dye. Any recommendations? Anyone used SEM soap and Plastic Prep?