Very interesting, I'll have to check into that! I use a Griffin FM transmitter right now, works OK, but has frequent problems with competing radio stations.
Definitely get yourself a car radio that has Bluetooth audio man.
Once you hear the music from your device coming on your car speakers with out the need for wires you'll never go back.
Whats interesting that I learned about it once I got one came from the way I bought it. I made sure that it had a usb, a 3.5 mm jack, and bluetooth.
USB - sound quality is best but you have to use the radio user interface to interact with your device and play music, a ui which is terrible. Also on my HTC EVO the USB port doesn't stay connected reliably
3.5mm - not noticeably above radio quality still needs another cord
Bluetooth - better than radio quality audio (though not quite as good as the usb), no interference and no wires. I use this most of the time as not having to hassle with wires or the usb disconnecting interrupting the music is great.
ipod - Also almost forgot, if you use an ipod for your music most car radios nowadays have a special mode for them and the audio quality is awesome. (Like crazy almost CD if not CD quality awesome)
I have a Griffin device and you can set them into "international mode" which lets you transmit on frequencies that aren't used by US radio. It works great for me, this review appears to contain instructions for your particular device: http://www.amazon.com/review/R26BNQ42BQKKE9/ref=cm_cr_rdp_pe...
Because (with few exceptions) you lose steering wheel controls and thieves become a lot more interested in smashing your windows. Also, my radio is nonstandard size and the adapters are fuuugly.
http://www.overstock.com/Electronics/Griffin-RoadTrip-iPhone...