Born 1915 in Germany, Heinz Brendel was more or less predestined for a career in motor racing. Passion for the sport ran strong in the family, with his father already enjoying success as a professional driver. In 1935, the young Heinz contested his first big race in the 1.1-litre class, finishing as runner-up in the Eifelrennen. After further success in classes at the smaller end of the engine range, Brendel was invited to test-drive a Mercedes-Benz W 25 at the Nürburgring. Unfortunately, the test was brought to a premature halt by an accident.
In 1937, he was selected by Mercedes-Benz racing manager Alfred Neubauer to test the W 125 at Monza. This resulted in Brendel being signed as reserve driver. In 1939, he participated for the first and last time in a Grand Prix event. Following a strong fifth place in qualifying, Brendel was told to hand the car over to Hermann Lang for the race itself. Instead of following instructions, Brendel drove on and was involved in a collision. A later test at the Nürburgring ended with the car going up in flames and a trip to hospital. After the war, Brendel drove for Porsche on an irregular basis.