I had them, the problem was they scratched the rims, came out of California. but that was in 01, they were called "wheel modifyer caps" or something and available in chrome and painted. If you dont have the scratches you can find small gold emblem caps, they dont cover the bolts.
http://www.performanceproducts4benz.com/productpage.aspx?cid=5&sid=377&pid=100671