it's a 13pin on one end, rca female on other. dunno if it'd work on symphony but crutchfield has 30 day money back, so no worries.<ul><li><a href="http://www.crutchfield.com/cgi-bin/S-xIWG9s7m1ne/ProdView.asp?a=1&amp;s=0&amp;cc=01&amp;g=50900&amp;id=essential_in fo&amp;i=113CAC1AX">from crutchfield</a></li></ul>

Audi has specific protocol and frequency signal properties in the CD changer that allow it to communicate with H/U.
Simply tapping into the line-inputs to the CD changer will not open the signal necessary to open the input to the H/U.

If you notice, the ad states this is for use with Kenwood changer, not Panasonic, and not for systems that have specific protocol signals.

Nice pick-up, but no-go here.

<img src="http://www.rcainput.com/Merchant2/graphics/00000001/product-audi_aux_v1.jpg"><ul><li><a href="http://www.rcainput.com/Merchant2/merchant.mv?Screen=PROD&amp;Store_Code=RCAI&amp;Product_Co de=AUD-AUX&amp;Category_Code=audi">Audi Adapter</a></li></ul>