The Arizona Republic. Go here and you can start your search:
http://www.azcentral.com/class/auto/
They also have a cars.com link, but I haven't had as much luck with that search as just their normal classififeds section. This weekend should be when the listings go crazy.
Might also check out the
www.traderonline.com website, as they may have some increased Arizona listings due to the auction.