My concerns would be aesthetics and fabrication to make it look good in the dash. For example, I would assume there is a wireless card built in with a small power switch on the bottom (or front) facet... working around those little parts for fabrication would suck.
Another random thing is space. I assume there is a specific power jack and a dc converter for this thing... where are you going to put them? BETTER and COOLER YET... Is there a docking station that you could modify into your build?
If you could get it working like a removable cd player face, that'd be pretty cool... I'd be very interested to see if you come up with something.