Review, drive and history of the awesome, unstoppable, Unimog 411 Westfalia. This rare model has a 30% bigger cab called the DvF or Type D (verbreitertes Fahrerhaus) or widened cab it was a limited edition Unimog truck made by Westfalia, a German coachbuilder/convertor. Fitted with the OM636, a 4-cylinder, 4-stroke diesel engine, available in Mercedes-Benz passenger cars, vans and small trucks since the late 1940s.