Most of the moon hubcaps don't take a crest. The nipple hub caps (2 styles available - low (shown) and taller (like Empi) are usually the crested ones. Depending on whether 4 lug or 5 lug VW or wide 5 they are different caps. Old 356 ones will not fit VW wheels. Due to PORSCHE copyright enforcement the crested ones with STUTTGART on them are hard to find. EMPI crested cap emblems can be removed and real Porsche emblems can be applied.
http://www2.cip1.com/ProductDetails.asp?ProductCode=C13-10-1058
http://www2.cip1.com/ProductDetails.asp?ProductCode=C13-10-1056