A hovercraft.
I have dreamed of a hover cart for years simply because I get fed up with all the cables on the ground.
Actually this is a bad idea though because imagine the dust and metal chips that would fly once the hover cart is turned on
Actually just build a cart that is simple. Plywood, metal, or extruded aluminum.
Just keep in mind to keep the wheels big in diameter as there is power cables all over the pits and arena areas.
Small wheels = lifting robot and cart over many cables many times...
Trust me, I found out the hard way.