Joe,
Mobile site looks pretty good! I gave it a spin on my iPhone, and I dig the larger-than-average photos of the inventory--too many sites (perhaps my own included) think phone screens are where they were in 2003.
Only two things I noticed: first, the logo across the top seems to have suffered in the shrinking--it looks almost jagged, and definitely doesn't seem to match anything else on the site. Also, longer vehicle names (e.g. "2011 Chevrolet Colorado Work Truck") get pushed below the image in MobileSafari, which threw my eyes off when trying to scroll through listings.
Keep it coming!