Have you ever tried using Vaseline on the bottom of the rear quarter panels? I know its a bit messy, but all you gotta do is hit the quarter car wash and rinse all that crap away. Apply it very thin and when all the rubber goes up, it goes up into that Vaseline. I must say that there's nothing wrong with mixing wax, but I'd stay away from actually mixing the contents of the bottles together, that's what I though was meant when I first read this, silly me!