The recently unveiled Mercedes-Benz BlueZero concept vehicles are built with the flexibility to insert electric, plug-in hybrid, and fuel-cell technologies into the same exact vehicle design.

It’s easy to dismiss the BlueZero sketches as just another cool green concept car that will never see the light of day, but it could be a glimpse into a future lineup of small Mercedes cars with varying degrees of electric power.

Definition: B-Class

The term B-class refers to subcompacts about the size of the Ford Fiesta or Hyundai Accent. The A-class is slightly smaller, although not as small as a Smart car.

This is not the first time that Daimler, the maker of Mercedes and Smart cars, has taken a Swiss army knife approach. The first generation Smart car was built with a “sandwich” platform that can handle conventional gas engines as well as alternative powertrains. In addition, Daimler used the A-class as the basis for 60 F-Cell fuel cell vehicles running on the streets of Berlin and Los Angeles.

Daimler F-Cell fuel cell vehicle
Smart ED in Berlin

Flexible designs allow a Mercedes A-class to take a fuel-cell drivetrain, and the Smart ForTwo to go electric. These vehicles are running in pilot programs in Europe and California.

Daimler previously announced that its next generation FCV will be built on the B-class chassis in 2010. Migrating to the BlueZero should only be a minor adjustment. Daimler’s future electric cars could also shift to the BlueZero—because the guts of the electric cars already fit in the smaller Smart and A-Class.

General Motors adds steroids (and fantasy) to the idea of building in flexibility. Its “skateboard” design potentially allows consumers to swap out various car bodies, seating configurations and power systems. That’s also the core idea behind GM’s “e-flex” architecture—the underlying basis for the Chevy Volt. GM swapped out the Volt’s 1.0-liter three-cylinder gas engine with a 1.3-liter four-cylinder diesel engine, and modified the body style, to produce a plug-in hybrid concept for the European market: the Opel Flextreme.

The General Motors futuristic “skateboard” design, as described on The Discovery Channel.

Sharing platforms and technology architectures allows car companies to telescope development and production timelines, which can stretch out for years. And it helps to save money on rolling out advanced new models at a time when cost remains the biggest obstacle to introducing the latest whiz-bang auto technologies.