I use a chinese Eonon Double Din unit. $200 on ebay, comes with DVD playback, MP3, GPS, TV, Bluetooth, 2 SD card slots, etc etc etc. The only thing I can think of that it does not have is a built in computer. Its an ok unit, its not very intuitive and the screen is no where near the quality of the Dx but it links upto my phone and plays Radiotime and Pandora for me. GPS works ok but takes forever to input addresses unlike the Dx. I was using the GPS on it before I built my Droid x case with vehicle mount. Now I use it because the GPS gives live traffic reports.