Yesterday, here in Japan, Sony announced their latest car navigation system, the NV-XYZ 77. For one, it shows models of the actual buildings so what you see on the car navigation system is extremely recognizable.
Second, it has a built in 30Gig hard drive. You can easily detach the system which is about twice the size of your average PDA and then you can connect it to your PC using a supplied cradle and upload updates to the maps as well as other media like MP3s!!!
Now we just need someone to port XBMP to it!