I remember this car from growing up near Milwaukee. Probably was on display at the state fair and other public events. I also had the opportunity to work with Brooks Stevens Industrial Design while working at Generac. Minor correction to the video: Brooks setup the company for his two sons to run, so personally had minimal involvement in the design. Likely BSID built the prototype as they also built prototypes for Studebaker and other small manufacturers, plus produced the Excalibur.
They explained that in the video... they just swapped lead for lead after doing slow ramp tests to make sure the rest of the electrical components were in good condition. They also replaced eh tires and did a general service on the vehicle.
The 40 year old tech it was designed with just get it going for the shoot. Then they explain theyre coming right out for modern tech that will double to triple its range.