Besides the language cassettes, the head unit is a must as my Rio has no tuner modulator (and they're not exactly the easiest things to come by)

Also, the CD changer is a must. Scenario: I pick up someone for a date:
Her: "hey I just got a great cd, let's listen to it on the way to..."
Me: "Um...if you let me take it home, rip it to mp3, and upload it to my Rio, we'll be jamming in about 1.5 hours."

Don't laugh, it's happened. With anyone who comes along and brings a cd they want to check out. Rio's rule - for the owner. Though awesome - they're not always practical.

And the changer is flush mounted where the top folds down into, so all you see in the trunk is the sliding door. It's not like I'm losing space with it.

Thanks for the ideas though...at least we have a start.