I didn't have much luck with SEM on my plastic seat trim. I have a coupe and it is the piece near the hinge where the seat back folds forward to allow access to the back.
The paint went on great... the color was much lighter than my Palamino interior is today (shouldn't it be the other way around) I cleaned the parts first with soap, then lightly sanded to remove the original flaking pieces, then sprayed about 3 coats or so...
After one year it is flaking off...
Here is my original post
http://www.peachparts.com/shopforum/showthread.php?t=180176