That's probably the easier solution to mine, but same premise.I had the same problem getting my radio out, the wiring harness had gotten caught and would only pull out about a couple inches. Take your ac controls out so you can get your hand up underneath behind the back of the radio when you pull it out a little bit and pinch the clips on the back and unplug the wiring harness. And no, there is no aux hook up from the factory, however I am using the iSimple Gateway and it is working well for me.
Being able to use the wheel controls is exactly what I wanted to know, guess I'm using some birthday money on that. Nice avatar, I'v got a 71 I'm gonna restore one day.I purchased the USA-Spec version that was recommend by various people in this forum - do a search on it. Anyway I think it is model #PA11-GM. It goes into one of your XM outputs, so you can still use one XM if you have it. It uses your stering wheel controls and everything. Took me a few hours to install, nothing to to crazy & I love it. Oh ya it charges your ipod too.