Belkin TuneFM for iPod

I'd like to start using my iPod in the car during the commute to and from work.
Looking to get the best possible sound.

The factory radio in my car is Levinson, so it has a decent tuner, but, there is no iPod interface.

I came across this device from Belkin called TuneFM.
Anyone using this in their car? How does it sound? Any serious interference issues on the highway that may become annoying?

Thanks for any thoughts and ideas.