RUF Automobile GmbH is a German automobile manufacturer. RUFs are built from unmarked Porsche bodies and chassis. When a chassis arrives, RUF builds their own independent work into the car. Because RUF installs many of their own-made parts (not to be confused with badge engineering), the company is recognized as a manufacturer by the German government. RUF is mostly known for their CTR Yellowbird, and is the biggest and most renowned company to make Porsche performance enhancements. RUF has also made a name for itself as an automobile refiner, specialist in vintage restoration and rebuilds of classic RUF and Porsche automobiles. RUF also carries out service and crash repair.