Picture from here.
We thought it looked pretty cool, and we got to stay behind it for a little while. When we stopped at a red light we witnessed the two side wheels fold down to balance it while at a stop - notice the black wheel on the rear of the vehicle in the picture above (it is folded up in the picture).
I just did a little googling to find out more about what we had seen. Go here for a pretty good description. After reading that short article, you should be stunned to find out how much they cost! Around $82,000 - granted it does have air conditioning, navigation, cruise control, and seats 2 - but boy that's a hefty price tag.
So, little did we know what we were actually seeing this afternoon!
Go here to see it in action or just put Monotracer into the search bar on youtube to see more.