Tell me about it. I've been looking into buying a new car, but finding one with two DIN slots is damn near impossible. Heck, even ONE din slot is too much asked these days.

Well, as somebody who's planning to buy a new car before the end of the year, I can say that this issue is very much on my mind. I've practically eliminated the otherwise intriguing Mazda RX-8, specifically because of its bizzare, proprietary stereo system. The only car manufacturer that seems to be bucking the trend is Subaru, selling the WRX STi without any stereo or speakers, but with the speaker wiring pre-installed. Never mind that it's also an insanely fast car; it's everything a stereo installer could want.

(I only wonder if Subaru ran the speaker wiring to the head-unit area, or whether they run it all to the trunk, where you might put an aftermarket amplifier.)

The other helpful trend is the spread of satellite radio. The Infiniti G35 Coupe's stereo has an external input for a satellite tuner. You could possibly hack an empeg in through that. Other manufacturers might be similarly planning some expandability into their factory stereo systems.