4th gens are a little different, Matt..
You can place some 7" flat screen monitors in the place where the stock double din HU would normally be. Then you can mount a single din sized HU below that (I think it's an ashtray?). Lots of people on the org have done it, of course, no one can access that now.
I know my girlfriend has a 97 GXE and I beg her everytime I'm in her car to let me install a screen + aftermarket HU and DVD