The carts are for "Bell Services Use Only". There is a tag on each cart that reminds you. We were told that they don't loan carts due to insurance reasons. At BCV the Valets unload your car and put your stuff on a cart. They call Bell Services who delivers to your room. Tip for valet and tip for Bell Person. A lot of Disney processes are designed for the maximum tip. At SSR, Bell Services will pick up your luggage from your room, (pay tip), then they check your bags while you wait for ME. When ME arrives, the move your bags from the check room to the bus. (Pay tip).