RENNtech is an American automotive company known for their work on performance modifications for Mercedes-AMG cars. The company was established by Hartmut Feyhl in 1989. Over the years, Renntech developed high-performance products for virtually all Mercedes-Benz AMG vehicles and more recently, the company started offering products for other marques such as Audi, Porsche, and Volkswagen vehicles. Aside from manufacturing high-performance products, Feyhl and his company are a prominent Mercedes-Benz specialist. High performance Mercedes-Benz cars developed by RENNtech were featured in several automotive magazines.