The Dual Can or Twincan was used to help boost the torque from the small can motors I use on these cars. If you remember the Porsche 911 I sent into the Brass am, it had a single can motor.
On my small home track this set up is ideal, and produces a very balanced car to drive. These motors only turn 16K at 12 volts, and when run at 10 volts there are really anemic, and as a result the proxy car Porsche 97 I have running in the TransAm is battling to stay out of last place. Twining the motors has increased the acceleration, but unfortunately the 16K is still 16 K so the top end is not there for proxy racing.
Again though with my home track and straight limited to 11 feet, I get lap times that are almost equal to Cars with 21K 130 can motors.
The chassis is a gift card with a brass plate. Axle blocks are Lego. The rear blocks have 3/32 bearings, and the result is a free rolling chassis.