Here’s a slick ride; the Acabion GTBO. It looks like it’d be more at home on the deck of an aircraft carrier or falling from the bomb bay of B-1, but it’s actually designed to transport two people at extreme speeds — top speed is limited to 279mph, but ungoverned it’ll top 370mph — and get better gas mileage than the thriftiest econobox.
I don’t know about you, but it seems to me that if you’re going to be moving at speeds like that you’d also want to be able to stop in a hurry. And the two tiny contact patches provided by the motorcycle tires on the Acabion probably wouldn’t give the traction needed to slow it down very quickly. As cool as this thing looks, that and the comments you’d get from bikers at a stoplight — “When you gonna lose the training wheels, Juniior?!” — would probably keep me from ever getting one.