Before their creation, no one could have guessed how popular the Volkswagen Beetle and the Kombi would become, or the passion they would ignite among enthusiasts. Raced, rallied, converted into mobile homes, or meticulously restored for the concourse show circuit, these cars are being driven in ways manufactures never imagined. That’s the problem.

Under stresses they were never designed to handle, old engine and transmission setups just aren’t reliable. This has been a source of frustration for owners of old VWs, who install powerful engines (or tune the old ones) only to break the gearboxes all too frequently…

An upgraded gearbox seemed to be the answer. With limited replacement options, the candidates were Porsche and Subaru. Porsche is the easiest conversion, and works well, but is prohibitively expensive. That left the modern-day Subaru, with its boxer engine, and in the turbo models (enough power to give you whiplash if you’re not braced at acceleration), coupled with a gearbox able to handle the power.

So, what’s the obstacle? The Subaru uses a front-mounted engine and transaxle, with All Wheel Drive. You have to get rid of the center diff for a start. Even then, a powerful engine mated to a modified box from a WRX into the rear of a Beetle or Kombi will make the car will go — but backwards. There was simply no manufacturer building modern gearboxes designed for rear-wheel drive cars, other than Porsche.

Back to Subaru — there was the pinion gear, rotating counter clockwise, meshed with the crown wheel, which also turned counter clockwise. On a rear engined car, this would result in the wheels being driven counter clockwise, pulling the car backwards. So, we flipped it. We worked out how to flip the crown wheel so that it meshed with the pinion on the other side, then the crown wheel rotation would also be clockwise.

The modified VW would be pushed forward rather than dragged backwards. You’re welcome.