So using your “logic” if the employer forbids employees to keep a hammer in their car, or a knife, they must comply?
Ridiculous. Property rights do not extend INTO my property.
The property in “property rights” refers to land or a house, not personal property like a car or a briefcase.
A person who owns land should have the right to say what can or cannot be on his land. If he wants no guns on his property (land), then so be it. That means no guns in your car - or in your briefcase - when you are on his land.
I know that this leads to a clash of rights, land rights vs. 2A rights. But it should be remembered that the Bill of Rights is meant to protect you from government tyranny. It is not meant to give you special privileges when dealing with private individuals.
You might not believe it, but I am a huge supporter of the 2A. No gun permits should ever be needed. I even believe that when a felon has completed his parole or probation, he should automatically get his 2A rights back. No lifetime ban as there too often is now.