The Tubi system would NOT sound good on an M5!!! I admit, the system sounds great on Ferraris--no doubt about it. However, the M5 is supposed to sound mean. You put a Tubi on the car, and it sounds like a Asian guy who got nailed in the groin really hard. For real, I know a lot of you posters know what I am talking about. The sound Tubi's produce is soooooo high. If you are a REAL M5 owner, you wouldn't disgrace the M heritage by putting one of b**ch systems on it.