I've loved these things since I owned a small hot-wheels version of one when I was little. Its another car that I've always wanted to own, but in this case its unlikely that I will ever be able to own one. There were only 3 prototypes ever made. Mercedes made the prototypes to be able to showcase the power that could be delivered by a rotoray engine, and did quite well with this car reaching over 200 mph. The 3 prototypes were made in the late 60s and early 70s, but I'm not sure the exact dates (I do have it, but not as I'm typing this). The data that I have is from Daimler-Benz directly in Germany. I wrote to the headquarters in Germany asking for information on these cars, and what they sent me was actual 8" x 11" photographs (B&W) from the 60s, with handwriting on the back. I dont know if these were the original copies from a file somewhere, but they sure looked like it. I will scan them in someday and post them.