Way back in the corner of the Antique Car Museum of Iowa in Coralville is this display. It’s the first diesel powered vehicle to achieve 300 mph. It was built by Roy Lewis of West Branch, Iowa. Roy took it out to the Bonneville Salt Flats every summer during speed-week. Ironically, a British team was out there at the same time also attempting to set a record with their diesel rocket car. But the Brits were topped by a small town Iowa guy.