Potentially the most expensive car to ever go to auction at Christie’s, the 1939 Audi Auto Union Type D was expected to sell for as much as $12 million. It was eventually acquired by Audi for an undisclosed price. There is so much history in the Auto Union Type D. To begin with, the car’s design was produced by none other than Ferdinand Porsche. The rear-engine design delivered unpredictable oversteer and Porsche attempted to counter this with a swing half-axle suspension before following the Mercedes lead and going with a de Dion system. The twin-supercharger V-12 delivered amazing horsepower and was known to break the rear tires loose at 100 mph. Tire slippage was an issue addressed by another Porsche innovation, the limited-slip differential. All this technology was developed during a period of state-sponsored motor racing. The success of the Auto Union Type D was ended by the course of Germany and World War II. When the war was over several Auto Union team cars were found by invading Russian Army forces and taken as spoils of war. These cars were disassembled and studied by the Soviets until, in the 1980s, American car enthusiast Paul Karassik tracked down chassis number 19 and many Type D original parts. Karassik handed over the collection to noted restoration shop Crosthwaite and Gardiner and the Type D was restored to its original form. With a top speed in excess of 200 miles per hour and that thundering, whining V-12 behind the driver, there isn’t another driving experience that can match the Auto Union Type D.