Legally can they enforce this. They don’t own the cars. Do the drivers buy the pizzas from Domino’s or are they on the clock? Yeah, they can require you not bring a gun into their store but I’m not sure about your car.
I am pretty sure you are right. I think the drivers are independent contractors. They work for themselves. Dominos does not pay any S.S. taxes. But they still have the right not to allow them to deliver their pizzas.