HERE IS AN EXPERIMENTAL car that has only two wheels. I believe it may have been Ford that experimented with this. It had a "self correcting gyroscope" to keep is from tipping over. I seem to remember reading about this one 40 years ago, and there was a problem getting it to stay upright when you parked it. The Gyro used a lot of energy, and could take 10 minutes to speed up to an RPM so we could trust the car would not tip over. Also, when it was parked, the Gyro exhausted the battery power very quickly, and than the car tipped over. If they could just work out the power problem, it would be a fun car to drive around in. It sure would turn heads - - .