A prototype of the 2015 BMW 7-Series Plug-in Hybrid malfunctioned on a public road in Germany.

Our spies say the vehicle was beyond immediate repair as the driver was waiting for the tow truck to pick it up and transport the prototype to the technical center. It was clearly the plug-in hybrid version of the next-gen 7-Series judging by the "Hybrid Test Vehicle" lettering on the rear bumper camouflage and especially by the charging port located below the left mirror.

The next generation 7-Series will be launched sometime next year and according to BMW's chairman Norbert Reithofer it will set an "example in terms of weight reduction" thanks to the implementation of carbon fiber in the vehicle's "intelligent composite construction."

As far as design is concerned, it won't be a major departure from today's model but nevertheless the next 7-Series will be a "very innovative car." Without any doubt, the plug-in hybrid version seen here will be the most frugal 7-Series ever made but probably won't come out right away.

Gallery: 2015 BMW 7-Series Plug-in Hybrid prototype breaks down in Germany (spy photos)

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