Hello I'm new to forum...I have 06 STS V6 without navi..I want to add a aftermarket tv radio into the car. But it seems as if the radio controls all of personalized functions (memory seats, chime, fob info etc) .Can I add TV radio n keep factory for my personal functions ???? Or do I just have to get factory Navi (because I need link to hook up ipod or mp3 player)????