Not sure it is trailerable but Coleman make a nice cover and it was only $43 on Amazon vs the $200 Yamaha wants. It fits really well and the material is plenty thick.
Measures 120" x 58" x 70"
300D x 300D polyester cover
Heat resistant material sewn under cover as partial liner
Accessory pocket for gloves and sunglasses
Elastic bottom with hooks for securing cover
I never noticed any pockets or hooks but I wasn't looking either. I just now noticed that in the description.