I've got the proper T-equipment ipod interface for 997.1 properly installed by a Porsche dealer for a proper 500 Euros ($750). I find the sound quality somehow inferior to the CD drive playing the same MP3 tune. Another disappointment is that the ipod battery does not charge through the interface. A simple jack into the preamp would have done the same job for a mere 5 bucks.

Does anyone have an experience to share?

I think it sounds similar to MP3's on a CD. They are both mediocre.