My wife has a 2006 TL and we are buying a new car. This means that I'm going to get the 2006 tl and my wife will be driving the NEW car. The TL has the standard radio unit fm/am/xm/etcf(without Nav). Now the questions in no particular order. Can I buy the oem nav system and install it. If so where? Are there kits for aftermarket nav system? IF I have to stay with standard radio- what is best iphone adapter for system.

Thanks