The Porsche 904, also known as the Porsche Carrera GTS, was designed by Ferdinand ‘Butsi’ Porsche and introduced in 1963. GT Homologation rules stated that at least 100 examples needed to be produced in a twelve month time period. Porsche knew that selling 100 race cars would be difficult so they built the 904 as a street legal race car. Three prototypes were built and tested vigorously near the close of 1963. Modifications and enhancements were applied and the 908 was officially displayed to the public in November of 1963. In less than a month after its debut, almost all 90 examples were spoken for and by April of 1964, the 100 units had been constructed.

The flat-four cylinder engine was placed in the middle of the car and powered the rear transaxle. A 5-speed manual gearbox was matted to the 356 Carrera 2 derived engine and modified to produce 180 horsepower. The potent engine and low weight of the vehicle, 1430 pounds, the vehicle was able to achieve a top speed of 160 miles-per-hour. A flat-six engine, in development at the time and being built for the 901/911 model, was intended to be used but was not ready in time. Some 904′s did receive a six and eight cylinder engine throughout its 2 year production life span, these vehicles were referred to as 904/6 and 904/8. Not enough of these larger engine versions were built to be homologated so they raced in the prototype class.

The body production was handled by Heinkel, an airplane manufacturer who was able to produce two per day. To increase the rigidity of the chassis, the frame was bonded to the body.

In 1964, 100 examples were produced. There was such a demand for the 904 that an additional 20 examples were produced in 1965.