Talked to the PO. He said that it is an FM modulator which should work through FM 87.3 Problem is there is no 87.3 that can be accessed through my radio, nor do any other stations pick it up. Oh well, FM would suck anyway.

Pulled the changer which is busted too, so looking at replacing it with a blitzsafe bluetooth module which connects into the old changer harness. Here's the vw version. Blitzsafe - VW / BLUETOOTH V.5T