Thanks for the info. Does anybody know if the BTUM works with all the phone systems? I was just curious in case I go that route. Although I'll probably do the retrofit if ever able to get a snap in for the Razr. I've heard some different things about the BMW phone system. Is there more than one phone that can be used in the system, or just one particular one? And if it's only one particular phone, how do you know which system you have?