Im going to place an order for a '06 A4 with the tech package. I would prefer to not get navi now and add it down the road if needed. But if I do it this way will I have to get a new bluetooth unit to go with the navi or will the bluetooth that comes with the car remain useable? (Im asking this because I was told by someone that if you get the tech package without navi the blue tooth unit is part of the symphony II radio and if you remove the symphony II to install a RNS-E you'll be removing the bluetooth too.) If I would need a new bluetooth, it might be cheaper to get nav upfront. Anyone know the truth? TIA.