http://www.ebay.com/itm/M-PERFORMANC...item25b6516bd3
FYI, BMW of Morristown has the diffuser listed for $949.99 with free shipping for the past couple of months now. no discount codes, no other gimmicks. their eBay store might not have a lot, but the most important stuff are listed with pretty much the best prices on the net.
but 25% off all of the lifestyle stuff is a good deal.