Zender GmbH was a vehicle tuning company founded by Hans-Albert Zender and existed from 1969 to 2008. The company cooperated with Ford, VW, Fiat and Opel.
In 1983 Zender created the Vision 1 design study based on the Audi Quattro, which was followed a year later by the Vision 1S. In 1989, the sports car prototype Fact 4 Biturbo premiered at the IAA in Frankfurt, the first street-legal sports car in the world to be equipped with a monocoque made of carbon fiber reinforced plastic. The Fact 4 Spider followed in 1991 as an open version, followed by the Progetto 5 in the mid-1990s. In 1999 the Thirty Seven appeared with an output of 230 hp and a top speed of 253 km/h.
In 1999 the Zender Thirty 7 was presented at the IAA Frankfurt. Shortly thereafter, the Roadster Straight 8 was presented. It had a 3.2 liter six-cylinder BMW engine with an output of 321 hp, which gave it a top speed of 250 km/h.