The most keenly anticipated BMW in years has leaked ahead of its Shanghai auto show debut due at the end of April, 2011. BMW’s fifth-generation F10 M5 was shown to some media at an exclusive preview in Germany with a strict embargo until April 7 but somebody simply decided to break the embargo and post some captures of the new M5 online. Bless them - now we don't feel guilty about doing the same.Although the production car will in all likelihood bin the black wheels, all other styling details should be retained and, truth be told, this could be the most muscularly elegant M5 since the E39.EIGHT-SPEED RUMOURPowering the new BMW four-door supercar will be a tuned version of BMW’s 4.4-litre twin-turbo V8 that's capable of more than 400kW sent to the rear wheels (only) through a seven-speed dual-clutch transmission. Initially there were rumours that BMW would simply convert ZF’s excellent eight-speed auto for use in the M5 (due to the associated difficulty of securing a supply of dual-clutch transmissions strong enough); fortunately this decision was overruled by engineers. One of the tastier rumours concerning the new M5 is the possibility of a six-speed manual transmission being made available – although only in North America.