Thanks! I purchased the bumper on eBay. The rear bumpers seem to be the cheapest and easiest to find. They can be purchased for $300-500USD depending on condition and whether you have them repainted. I purchased this particular one for $300 and it had already been freshly repainted to factory specs. I spent an additional $100 in parts at a BMW dealership for the OEM parts needed to mount it (see list above). So, IMHO, its a fairly inexpensive upgrade that dramatically enhances the look of the 2004-2005 X3's black bumper.