I have the Belkin car charge with the audio-out jack, but that still requires an FM transmitter. You post says that the audio shop "hardwired it into the car and to the stereo."
I found your post in the "Modifications" thread that says you're using an FM transmitter. Is that the case...or did you actually find a way to connect direct to the stereo without the FM transmitter?
No matter what, pictures would be great.
Many thanks...