I'm looking to fit some sort of phone kit to my B7. It is very important to me to have an external aerial, principally because after having a car with one it makes for much more consitent call quality on the move. Does the OEM bluetooth allow an external aerial? More specifically is it RSAP compatible? My car is 56 plate B7 A4 saloon with Symphony II, BOSE and a MFSW. Cheers.