From the original Beetle, the product line was extended in 1961 to the larger, more modern Type 3 with a similar powertrain layout. A few years later, and even larger car was planned, again using that type of powertrain. It became the Type 4, marketed as the 411 (produced 1968-1972) and 412 (built 1972-1974).
This proved to be the last of that type of car, as the realization finally seeped in that it was to some degree a technological dead-end. The acquisition of Auto Union in 1964 led to VW adopting Audi water-cooled motors with front-wheel drive for future models.