Engine swaps are fun. Ridiculous engine swaps are even more fun. Ridiculous engine swaps done by the original manufacturer? Now you're talking.

Peter Wesp, the manager of the B-Class manufacturing plant in Rastatt, Germany, had an idea to build a special one-off model of the car. From there, Andreas Waerz, the foreman of the training facility at the plant took up the challenge, proposing that the compact car could be retrofitted with company's 5.5-liter V-8 and rear-wheel drive. As if that wasn't audacious enough, the project was handed over to the trainees.

The twelve trainees selected had some rigorous marching orders. They couldn't alter the shape of the B-Class, so no widebody kits were allowed. In fact, the exterior appearance of the car couldn't be dramatically different from the standard-issue hatchback. The interior had to be updated to reflect the premium driveline, and most difficult of all, the car had to be usable as a day-to-day driver.

To build the project, the trainees raided the Mercedes-Benz parts catalog. Surprisingly, the V-8 engine fit like a glove, as did the seven-speed automatic transmission. However, fitting a rear axle to a front-wheel drive car was no small task, so they designed and built a new subframe and used the rear axle from a W210 E-Class (1995-2002 model year). The driveshaft came from the same car. Brakes came from a C32 AMG, but despite the extensive use of existing parts, a lot of pieces were one-offs. The entire exhaust system was hand-fabricated, and the engine control module required extensive reprogramming to work with the new configuration. The only area that required outside help was the suspension, and the trainees went to K&W for a coil-over setup.

Inside, one-off Alcantara headliner and pillar covers were created, and the seats were reupholstered in an Alcatara/leather combination. The exterior was painted white and given black details, but true to the marching orders, there's little about the car's appearance to give away its hard-core driveline.

So how does it work?

Waerz says that they haven't conducted any tests yet, but that 0-100 km/h should take less than 6 seconds. He also notes with pride that the finished project weighs in at 397 pounds more than the car they started with, not bad considering the significant changes made.

Don't expect to see anything like this in a showroom -- in the U.S. or Germany -- anytime soon. However, if you can speak German, or are willing to learn, the job of a Mercedes-Benz trainee suddenly sounds a lot more interesting.