Well, I cannot sacrifice the small amount of storage space behind the rear seats, so I'll HAVE to do something with the spare tire area. How expensive would it be to have a custom fiberglas enclosure made to fit behind the stock plastic spare tire cover, and then cut a hole for the sub in the existing cover?

I haven't even STARTED looking for a good head unit/GPS system/LCD combo. And I'd definitely like a way to get the rear-camera system integrated into an LCD screen.