I drive a 911 Carerra S.
The system is nice (I have the Bose), very nice actually, but no way in hell is the Burmester high end system (+$8000) suitable for a car.
My previous ride was a BMW with a Harman system, again, very nice, but it's not silent inside when you're driving! I think what I meant was, it's nice to have a default "good" hi-fi system in a car, but when I see people actually replacing the drivers with Focal and Dynaudio drivers and use solid state McIntosh amps...that seems pretty pointless to me.