What's the module of your car? I know a online all-in-one car stereo store. They provide car stereo with builtin GPS bluetooth MP3 SD car extension and USB slot and etc. for special brand. What's more, the price is reasonable as I have purchased one there months ago
Here is the link Autodvdgps
from looking at the description, they don't have album art, and have very basic ipod control, ie video. if you are not too bothered about sat nav, alpine also do a double din version of the single din. Pioneer and Kenwood also do a double din with or without satnav. The Kenwood I have is DNX5220, it shows album art, but can be a bit pixalated, but has a nice scroll feature for song names, artists, etc, etc. The Pioneer has a better album art display, but does not have scroll feature for the song info.