To put the configuration in the proper context:
All cars entered shall be constructed from the BSA official kit.
o Race cars may weigh no more than five (5) ounces (total weight) as determined on the official scale during race day inspection. Weight may be added to the car by you and will be considered part of the car for purposes of all measurements. “Weight” is considered to be any material on the car that is not provided in the kit. All weight must be securely fashioned to the car, e.g. by permanent glue, nails, or screws. Weights shall be passive.
o Race cars may be no longer than 7 inches, and no wider than 2 3/4 (2.75) inches, and no taller than 5 inches, as determined by the official gauges during race day inspection. Underside clearance of at LEAST 3/8 (1.75) inches is highly recommended, so that the car will run on the racetrack.
o The car must roll on the wheels and axles from the kit we sell you. The axles shall be firmly affixed to the wood of the car body. It must be obvious to the judges that the wheels and the axles from the kit are being used. Wheel treatment (smoothing and polishing of the hub and tread) may not result in substantial removal of mass nor in reducing the tread (track contact) width from the original kit wheels.
And because these rules are authored by the Boy Scouts of America, all cars must be straight!