I would wash the car, that should help, use warm water.
Your tip worked. I let the car sit in the sun til the black war really hot, then did a Z-12 wash with 'hot' not warm water. As I washed the surface i went over the surface with a bare hand and this car now looks as good as new with the fresh Z-5.
End of Shaggy-Dog story
2001 Black 6-Speed Coupe - Absolutely perfect in every possible way!
[Modified by Dick Kriss, 12:27 PM 6/15/2002]