I use the size M for a REX Street 450 (ie a "normal" China Roller)
The tarpaulin fits perfectly over it, and is the material heaviness and thickness still easy even in light winds to install.
So far on my scooter and not a drop of water when I pulled off the tarp.
The Velcro underneath the vehicle initially looks short and not entertaining way, but has so far proven super.
Front tires are the two large plastic rivets through which I personally always put a short bike rubber band, so that even in bad weather the plane was perfectly maintained and protected.