The Crazy Cart is not designed to be used in the rain. Its motor, chain,
and sprockets would begin to rust if used in the rain. Its wiring
connectors, fuse holder, and power switch are not waterproof so their terminals might
begin to corrode also.
It certainly would run in the rain though and it has a low enough Voltage battery that there is no way of anyone getting shocked from it being wet. The only problem would be that it might develop problems down the road that could have been avoided by not using it in the rain.