BMW M, the famous automaker's subsidiary in charge of high-performance vehicles, has introduced its second standalone model over 40 years after the M1 was first sold to the public. The new vehicle is a plug-in hybrid model called the Concept XM, and it's apparently the most powerful BMW M car to ever go into series production. It will use the company's newly developed M Hybrid drive system that combines a V8 engine with a high-performance electric motor.