From the very start you have to have an aerodynamically clean design. Its a challenge to do that with the dimension rules in the Canary Derby, and also with the budget limit. At the speeds at which the competitive cars were running last year (34-37 kph at the corner, probably faster at the finish line), aerodynamic drag is the major force on the car. I’ll get into a wheel discussion later, but rolling resistance is a minor component of overall drag (except for the cars last year using soapbox and skateboard(!) wheels). The Carmanah Technologies car, had in my opinion, the best running gear in the field. They used racing wheel chair wheels and tires (700c?) and the test runs the week before the race were done with no body and were quite fast. But the body shape they chose was not very good, and I think that cost them the race. The Aspreva car had slower wheels (20″) but a faster shape (albeit not the best shape possible), and won.