We've sold PlasmaCars at Owls Hollow for many years now - they are really popular and support a lot of weight (up to 200 pounds).  They work best on smooth surfaces.

No batteries, gears, or pedals…just hours of endless fun. The Original PlasmaCar® – kid powered, kid approved.

Materials: body is ABS plastic and wheels are polypropylene.

Warranty: 1 year from date of purchase against defects in materials and workmanship occurring during normal use

Supports up to 220 lb. (100 kg).

Ages 3+