I put S-04s on my E60 M5 and loved them. They were a great tire. Never had a flatspotting problem at all and I never felt like they were noisy. Grip was outstanding.
2012+ 09 E93 335i - Space Gray, N54, Sport, Premium, Comfort, Logic7, Nav Mods - Reflectors, LUX, Pedals, M3 Spoiler, Black Grilles, Macht Schnell, Aero, ESS, RE760
2011-12 07 E60 M5 - Indy Red