Just bought my first 08 Impreza wagon last night and ripping out the stereo for a better one will probably be my summer project, so thanks for this thread, it was pretty helpful. I want to get sat. radio at some point soon. Should I just wait till I upgrade my stereo? The in-dash receiver is supposed to be sat ready, so I think there shouldn't be too much work involving that (at least I think).
*Just did some more searching around the forums and decided it's probably better to replace the stock HU and buy a separate XM receiver.