I remember seeing one that had the dual zone audio...meaning that you could have the rear speakers play the audio for the DVD, while the front play the radio and navigation directions. That way, the kids in the back can watch their shows and you can listen to music rather than listening to the movie.

I could not find it again on flea bay. I just thought that was an interesting feature. Maybe these units you are looking at has that, but I didn't see it mentioned.

Good luck. Let us know how either one of them turns out. I'm interested in getting one myself, but just haven't pulled the trigger yet. I have my old Alpine in there and I have a separate GPS unit so it's really not urgent for me...