BT OBD Adapter.
I'm installing a Nexus 7 where the BMW installed GPS unit goes.
Putting in a BT OBD unit with an adapter cable to locate it out of the way.
Will use the Nexus 7 for gauges, GPS (tethered to phone), V1 integration, media (Pandora, SiriusXM, TuneIn Radio and iHeart).
The mounting will cost about $40, the tablet $200, the apps less than $30 and the BT OBD reader less than $40.