The BMW 5 Series is entering ... the 540i gets a 335-hp, turbo 3.0-liter inline-six; the M550i xDrive gets a 523-hp, twin-turbo 4.4-liter V-8; and the M5 has a version of the 4.4-liter that ...

BMW M5 is part of an ongoing online auction, which will end on January 31. At the time of writing, the highest bid was $18,760 ...