Yamaha will be introducing a lot of new concept vehicles at the Tokyo Motor Show and the Yamaha Tesseract, a 4 wheel leaning vehicle ups the ante when compared to all of the other 3 wheel tilters coming out.
The Tesseract is a hybrid 4 wheeler, powered by both a V-Twin gasoline engine and an electric motor. The suspension is what they call a "dual-scythe" which leans while cornering, just like a motorcycle. It also has a dual arm lock to keep the Tesseract upright when stopped, just like the lock on a Piaggio MP3.
With everyone working on leaning vehicles with more than 2 wheels, it was only a matter of time before 4 wheelers adopted the technology. If concepts like this start to appear in production form, how long before vehicle laws have to change to adapt?