If you have a dremel tool or access to one use the buffing wheel with some sort of buffing compound and that thing will shine like no other(for the tips). The buffing wheels are much more gentle than steel wool so you could maybe do the same to the wheel lip as well. Since the tips are stainless steel I believe I would try to get a polishing compound suited specifically for steel for the best results.
Very true Richard. If it is a pre-03 car be sure not to get into the paintwork. Or if you have a 03 or 04 just remove the tip by unscrewing the nut that the holds the tip on and you can go nuts~!\! Have fun.
I polished mine using the "Flitz" metal polish with a Dremel-alike tool a couple of years ago. Came out with almost a "mirror" shine. Now it just requires an easy touch up periodically with the polish using a rag.