Last week I took everything apart to try and fix the CD changer. I saw how easy it would be to put in a double din. But I don't want to lose the navigation and I already own the DEH-80PRS which is a huge part of it. It's an audiophile grade head unit and I have no extra money to be buying a different one.
I did notice though, that there is an empty connection behind the stock stereo for the rear entertainment, which I don't have. I read that people were able to install aftermarket rear entertainment systems. So I don't think it would be impossible to the same with my head unit. The Rear A/V button would switch the input to it.
This appears to be the adapter for it, with minor trimming required.
http://www.amazon.com/gp/product/B0015G ... PDKIKX0DER
If I find myself unmotived, I'll probably just do the popular mod of splicing in an AUX port into that same input. Makes me miss my Forester, that car was an aftermarket audio sandbox.