I've been using the official Samsung pogo pin car kit for a while now but one thing bugs me about it.

When it's connected to my car via the 3.5mm audio connection it routes music, sat nav instructions and so on through the car stereo but when I receive a call the phone goes into speaker phone mode and routes the audio through the phones speaker. This usually means I can't hear what the other person is saying and thus makes it kind of useless as a car kit.

Does anyone know if it's possible to route the voice call audio through the pogo pins and ultimately into the car stereo?

I have the GSM GNEX running stock 4.2.2, none routed.