Tony, that truck is definately headed for some kind of pond, I just tried LA's Awsome, got it at Dollar General for $4 I think, half gallon. Stuff took MM enamel off really well, 24hrs and it's just white plastic. Far better (quicker) results than Purple Power.
I'm having the same problems with paint drying dull after wet coats, (see post) and I'm using the same kind of paint you are. Sounds like you are painting outside? Which is what I do, and , I think the high humidity causes the paint to dry dull. It's happened twice to me this week, once with Tamiya, and, today with Dupli-Color.
I'm not sure what's causing your paint to peel off though, some basic principle with tape, or , paint drying times, or , both that you're overlooking. I'll be following to see how things turn out for you.