GoCart Free Downtown Shuttle (Not The Bus)

Hola! Anybody have any experiance with the GoCart downtown shuttle? Is it really free? Are tips expected? I can't find any additional info or website for them.

Their bio on NoogaNightlife says this:

GoCart is an electric shuttle in downtown Chattanooga. We partner with brands like Coca-Cola to provide free rides and a great experience! Give us a call at 423-269-1100 to catch a ride • 6:00 – Midnight.

Thanks!