I am finalizing my order for my S. Two things knawing at me ... 1) Air suspension ... years ago I owned a Range Rover ... and it had some sort of leveling system on it; faster you went, lower the ride. I felt that it was a waste. Even the trunk lowered and I felt it was overkill. Does the S's "air thing" equate to the Range Rover? Or have any "non-air" models even been delivered yet for anyone to know the difference? 2) Premium sound. Has anyone compared the two? I drive 99% with nothing playing. But never been in a truly quiet car. Always felt that with road noise there's no point in luxury sound as the ambient noise makes driving with "premium sound" a waste of money.