No, we don't watch movies in the car, but I find that the center dash speaker helps center vocals as well and (most of the time; not always) gives a better overall soundstage. Don't forget, the way speakers have to be placed in a car, the driver is much nearer to one stereo side than the other. But what I'm quickly seeing (er, hearing) with the Bose system is that soundstage is VERY dependent on how the music is mixed. The Bose surround really expands the soundstage in some cases, but not so much in others.