Look at the Acura TL. It offers a DVD-Audio system specifically installed for that model. I'm currently forgetting which manufacturer provides the system but you'll find it on the web.

So far, I don't know of any manufacturers doing SACD in surround for the car. All hybrid SACD discs should play fine in stereo in a car CD player. Of course, that wouldn't be the hi-res track...

Hope that helps...