I just got my hands on my dream car, a 2005 e320 wagon. It is great, but has barebones stereo installed (no navi, bluetooth, etc.) What are my options...is it better to buy the phone cradle & bluetooth & navigation unit or is there a financially reasonable alternative? I sold my girlfriend to get this, so is it possible to find a new COMAND unit with gps & bluetooth already installed cheap, or am I stuck with a tom tom & hands-free kit?