Bluetooth handsfree kits are now being integrated into aftermarket car stereo headunits. I havent seen any reviews yet, but here are three units I googled:

http://www.audiovox.com/webapp/wcs/s...4442&langId=-1

http://www.parrot.biz/products/index.php?id=rhythmnblue

and

http://digitalsounddirect.co.uk/shop...s_id/1588.html