The Solo, like the Sparrow, is a tadpole with only the rear wheel powered. Traction control is a problem for such designs, and if uncontrolled, centripetal precession turns the vehicle into a spinning top.
John Lussmeyer had sEVeral "Sparrow spinouts" and might chime in.
The Arcimoto 2WD design is superior for slippery conditions.
My other comment was about rutted roads. In a 3-wheeler, each wheel is on a different track, so you'll feel up to 50% more bumps compared to a 4-wheeler with only two tracks. The narrow wheelbase also means that only one tire of the three will reliably ride in a rut. My narrow i-Miev is similar, but two wheels in one rut track straight and narrow.
The center of asphalt lanes tends to be higher and oilier than the two tire ruts, putting the vehicle at an awkward angle and setting up potential hydroplaning on that wheel in the rut, while the powered wheel is pushing on wet oil.
That's what I meant...