DSUS DS-400GB splits rear-view with GPS

We suppose the line of thinking with the DSUS DS-400GB is that you're probably already eying your rear-view mirror plenty, so why not just split off a third and throw a 4-inch GPS nav unit up in there? Not a bad idea, but don't you want to be looking forward -- not behind you -- when considering your next turn? Not that it's of any consequence, anyway, this thing's straight outta China with no US release or distro (yet).