I've heard this argument several times, and it isn't really germaine. Your property expectations as a homeowner are different that the expectations of a corporation which does business with the public. If you had a business where the public and your employees came and went in your driveway at will I would expect that you would have no right to say what they had in their cars.
I don't see how you can make a distinction between our *rights* to control what happens on our private residential property vs our private business property.
Again, I think that mindset falls into the liberal trap of thinking that businesses are public, not private entities, that their existence is justified by their benefit to the public, as decreed by the state.