I've read the multiple posts about devices that can be used to add an aux input (i.e., Ipod) using the wiring harness that plugs into the back of the head unit. I previously installed a factory XM radio using such a harness. My question is, can these devices be installed at the wiring going into the cassette deck? The connector that plugs into the cassette deck is a 12 pin that looks identical to the connector that goes into the head unit. It would seem that there would be a way to use the cassette wiring to add the auxilliary input, but I've not seen it. I don't care if this make the cassette deck inoperable. Any one try anything like this?