only two were made, the 1934 and the 1938. Yup, 4 years apart and the same model.. but that wasn't uncommon prior to Harley Earl's production changing concept of make the people want to buy a new car every year with constantly changing designs.
the first was gifted to Mohammed Reza Shah of Iran by the German government and spent most of it’s life in Iran, and was found by a Mercedes-Benz truck importer in the 1960s, the car was totally original with only 10,000 km on the odometer.
The second was completed in 1938 for professor Ingacio Barraquer. He was in Germany on vacation from his regular residence in Spain. Barraquer used this car often and went on many long journeys including a famous drive through North Africa. He traveled from Libya, Cairo then finished in Alexandria before the car was shipped back. He found it to be too difficult to maintain and replaced it with a more modern 300S. It was then given to his son-in-law and stayed in the family for decades. For some time it was loaned to Antic Car Club in Catalina who had it displayed in Barcelona.
Eventually, it was sold by the Barraquer family in 2004 (is now owned by Arturo and Deborah Keller) and restored by Paul Russell & Co. before making a debut at the Pebble Beach Concours d’Elegance. It won the award for the most elegant coupe and was a runner up for Best in Show. This was followed up in 2008 by winning the Coppa d’Oro Villa d’Este.
The design is so good, that many claim it inspired Bugatti to design the Type 57
http://www.supercars.net/cars/3604.html