Ferdinand Porsche developed the Type 12, or "Auto für Jedermann" (car for everybody) for Zündapp in 1931.
Porsche already preferred the flat-four engine, and selected a swing axle rear suspension (invented by Edmund Rumpler), while Zündapp insisted on a water-cooled five-cylinder radial engine.
In 1932 three prototypes were running; all were lost during World War II, the last in a bombing raid in Stuttgart in 1945.

The Zündapp prototypes were followed by the Porsche Type 32, designed in 1933 for NSU Motorenwerke AG, another motorcycle company.
 The Type 32 was similar in design to the Type 12, but it had a flat-four engine.
NSU discontinued car manufacturing, and the Type 32 was abandoned at the prototype stage.

Initially designated Type 60 by Porsche, the design team included Erwin Komenda and Karl Rabe.
In October 1935, the first two Type-60 prototypes, known as cars V1, a sedan, and V2 , a convertible (V for Versuchswagen, or "test car"), were ready.
In 1936 testing began of three further V3 prototypes, built in Porsche's Stuttgart shop.
A batch of thirty W30 development models, produced for Porsche by Daimler-Benz, underwent 1,800,000 mi (2,900,000 km) of further testing in 1937.
All cars had the distinctive round shape and the air-cooled, rear-mounted engine.
Included in this batch was a rollback soft top called the Cabrio Limousine.
A further batch of 44 VW38 pre-production cars produced in 1938 introduced split rear windows; both the split window and the dash were retained on production Type 1s until 1953.
The VW38 cars were followed by another batch of 50 VW39 cars, completed in July 1939.

The car was designed to be as simple as possible mechanically.
The air-cooled 25 hp (19 kW) 995 cc (60.7 cu in) motor's built-in oil cooler, and the flat-four engine configuration's superior performance was also effective for the German Afrika Korps in Africa's desert heat.
The suspension design used compact torsion bars instead of coil or leaf springs.
The Beetle is nearly airtight and will briefly float.
Ferdinand Porsche developed the Type 12, or "Auto für Jedermann" (car for everybody) for Zündapp in 1931. Porsche already preferred the flat-four engine, and selected a swing axle rear suspension (invented by Edmund Rumpler), while Zündapp insisted on a water-cooled five-cylinder radial engine. In 1932 three prototypes were running; all were lost during World War II, the last in a bombing raid in Stuttgart in 1945.
The Zündapp prototypes were followed by the Porsche Type 32, designed in 1933 for NSU Motorenwerke AG, another motorcycle company.  The Type 32 was similar in design to the Type 12, but it had a flat-four engine. NSU discontinued car manufacturing, and the Type 32 was abandoned at the prototype stage.
Initially designated Type 60 by Porsche, the design team included Erwin Komenda and Karl Rabe. In October 1935, the first two Type-60 prototypes, known as cars V1, a sedan, and V2 , a convertible (V for Versuchswagen, or "test car"), were ready. In 1936 testing began of three further V3 prototypes, built in Porsche's Stuttgart shop. A batch of thirty W30 development models, produced for Porsche by Daimler-Benz, underwent 1,800,000 mi (2,900,000 km) of further testing in 1937. All cars had the distinctive round shape and the air-cooled, rear-mounted engine. Included in this batch was a rollback soft top called the Cabrio Limousine. A further batch of 44 VW38 pre-production cars produced in 1938 introduced split rear windows; both the split window and the dash were retained on production Type 1s until 1953. The VW38 cars were followed by another batch of 50 VW39 cars, completed in July 1939.
The car was designed to be as simple as possible mechanically. The air-cooled 25 hp (19 kW) 995 cc (60.7 cu in) motor's built-in oil cooler, and the flat-four engine configuration's superior performance was also effective for the German Afrika Korps in Africa's desert heat. The suspension design used compact torsion bars instead of coil or leaf springs. The Beetle is nearly airtight and will briefly float.
Volkswagen Beetle