Johannes Beeskow worked as a designer at Rometsch and designed a 4-door version of the Beetle by extending the chassis and body by approximately 26cm in the centre. This allowed a rear passenger door to be added, which was hinged at the rear. It's not known exactly how many were made but it's thought to be about 26 to 28, ranging from a split window in 1951 up to Oval window models in 1953. It is thought that the introduction of the type 2 signalled the end of the cooperation between VW and Rometsch and the demand for Taxi beetles simply wasn't there to continue building them, so Rometsch focussed on their other Beetle conversions - the Beeskow and the Lawrence.

There is currently a 1953 version on display at the VW Museum in Wolfsburg, here it is on display at the Bad Camberg Vintage Meeting:

There is also a nice example in the Grundmann private collection:

These days an original 4 door taxi is a rare car, with only about 4 known to have survived. There have been a few other custom 4 door Beetles created over the years, including some from South America - but these tend to be non-stretched cars with small rear doors.