I put a layer of high tech yellow wax after I polished with Meguiar's crystal polish about two weeks ago. Now I'm thinking about adding another layer or two of polishes. Do I need to de-wax it first?

Thanks.

 

nope

 

I'd tend to say yes. Wash it with Dawn first. The polish is slightly abrasive and also acts as a cleaner. It will take a the wax off anyway, but it wont look as nice. It's ok to GLAZE in between layers of wax, as glazes contain no polishes or cleaners, just oils and fillers. Overall you will get a much better result from starting fresh. Multiple applications of polish have limited effects since all you're doing is scrubbing crap out of the paint and polishing out small swirls.