I kinda want it to be true ;-) This pic siggest they do hook it up to the 12 pin connector:http://www.installer.com/photos/gm12-aux-diag.jpgDoes anybody have a wiring diagram? I have seen a picture of M&T amp setup somewhere here....Best yet would be Delco radio schematics, but this is too much ...

There seem to be another product to do the same:http://www.autotoys.com/x/cata....htmland: http://www.installer.com/aux/ (look for GM12)All it means that the spare connector on the rear of our OEM radios is for misterious 'AUX' device, and the AUX button is not fake. I bet if we had wiring diagrams ...