You can use anything over just about anything else, but every step changes the last one in some way, either positive or negative. I have used a Polymer "QD" over wax and achieved real good results. But the product was not designed for this usage, and so, I do not expect that all the performance of the "QD" product to be the same as if I had applied it per instructions. The best thing to do is to experiment and see if the results are pleasing to you.