I feel guilty about not updating this, but because I'm still not entirely sure what the point of this thing is it's not entirely difficult to rationalize my procrastination.
I can use my iPod in my car now. It's really cool.
I had a cassette adapter in my poor old smooshed Saturn, so I used my iPod with a cassette deck adapter in there. My new (not so terribly new anymore, actually) Civic has only a CD player and radio, however, so the old solution was out.
Since I'm morally opposed to broadcasting on FM and using that particular hack (in no small part because of experiences with this technology back when I was living in Intelligent-Storage-Land), I decided to go with a thoroughly nerdy solution; I took apart my dashboard, hooked up a an adapter, and now my stereo deck think my iPod is a standard Honda 6-disc CD changer.
Obviously this is a suboptimal solution; the Belkin TuneDok (hate that name) is cheesy, despite being the least-cheesy solution available. Some day some car company will have the foresight to build an iPod dock right into the car, with automatic interfacing to the stereo. Or perhaps some kind of a general purpose area into which a wide variety of docking stations could be seemlessly inserted.
I should patent that.