Patented engine noise
 

I had a 2005 E53, I love the engine sound when I crusie on highway. the sound was very crispy and pleasant. my E70 doesn't have the sound anymore. my previous sales told me BMW applied patent for the engine sound.

Perhaps, but I doubt they got the patent. Harley-Davidsons have an even more distinctive sound, and the U.S. government rejected their attempt to patent (actually trademark) the sound. I doubt BMW would have any more luck than Harley did.