It was excellent actually, no real complaints. It got mixed reviews but I thought it sounded great; very crisp and clear, no distortion at all. About the only weakness was bass-heavy songs would get a little 'muddy'. Either way it's MUCH better than the overpriced shaker system in the mustang (which should be called shakey).
Overall a good system, but I'm dying to try out that 15 speaker HK in the Stinger.