You have a few options. One is that the FM transmitter for your iPod might just be a low quality one. I have several Griffins that have worked great (and give me the choice of any FM channel I want to use). If I'm traveling and get interference I simply change the channel and it's clear as a bell. Your alternative is to get an aftermarket iPod integration kit which doesn't rely as much on what radio you have, it slips between the radio and the wiring harness for the car and work great (have also used several of these). I would google "ipod bmw 325" and you'll find several out there (like http://www.bavariansoundwerks.com/ca...Fape7AodU0zCtg)