I don't know if you guys have seen it yet, however, there is a new serial based bluetooth module available at:
http://redferret.net/?p=5131
On the same day another company released a bluetooth OBD Transmitter:
http://www.vitalengineering.co.uk/
and we all have bluetooth phones by now right??

My empeg is long gone (I'm kicking myself now because I have a lot of bluetooth background) but it looks like you guys could have one hell of a project on your hands. Good luck if anyone wants to pick it up.

Matt