Well, since I'm not paying for it I'd say he should get a single din nav with a motorized screen. Install it above the empeg. A purist would plug the nav into the empeg, but if it can mix voice promts over it's aux input, do it that way.

For radio, sat radio, navigation and surround sound there are plenty of better options, but for listening to your own music collection, there's nothing that comes close to the empeg.

Matthew