I was going nuts on this topic way back when we first go this puppy and the elite hadn't yet figured out tethering. In general, I think this can be done, but have looked for it and not found it. I note that the new AS makes an IP connection to the phone on private IP addresses which seems routable (hence tethering). You could even do the tethering approach in your car, but that is nto a very nice answer. If all else fails, there are software router projects (XORP) that have open source code that could be ported to ARM. The solution you are looking for would have application way beyond your car stereo.