I've been looking into the D3 now for a bit and I luckily found this site which has answered alot of my questions. And I'm looking for the cheapest price like many others... anyways... I looked on the rebate itself through abtelectronics and then found the same rebate form from pioneer through a .pdf file.
http://www.abtelectronics.com/rebates/pdfs/pion_0d3_3-31-08.pdf
Reading the small print states...."This mail-in rebate offer is not valid at the following stores: Best Buy, Circuit City, Car Toys, Al and Eds Autosound, Tweeter, and Crutchfield. Call these stores for more information."
