Forgive me if this is a well known fact, but I thought I'd share.
Having the single DIN Concert unit which doesn't play MP3's, I had started a thread a few weeks back asking if there was a possibility in any way to play mp3's throught the headunit.
I was birthday boy yesterday (24 ) and with birthday money bought an ipod nano and a kensington FM transmitter. Its bloody amazing the ipod fits neatly in the ash tray (never used of course!) and transmits all the songs wirelessly to the concert unit and plays those songs as if they came on the radio. If that makes sense. Really love it, and sorry if this is old news and I was stuck in the past!