Ever consider bolting down a home theater amp and giving it a converted power input? you could have 5.1 and everything!

I've seen a number of head units with digital outputs but it's only designed to carry the signal near the amp, where it goes into another box to be converted at the last minute. I've seen a lot of stereos and browsed a lot of magazines over the years and never seen a car amp with an SPDIF or toslink style input. However with so many head units having built in DVD players and such these days, it's only a matter of time. Not that it helps you out now...