I am very interested in the quality of music coming out of a vehicle's sound system. I once owned a Hyundai Genesis...and bought the car because of it's outstanding sound system. One of the selling points of the car was that the sound system was the same as that used in the Rolls Royce Phantom. With all that said....how does the upgraded sound system rate in the Model S? I just reserved a Signature Series S today after being on the waiting list for some time. I will test drive the Model S in Houston in August...but was wondering what people are thinking about the music quality.