So your argument is that if you can manage to get your employer's property in your vehicle parked on his property, your employer has lost his right to recover his property because he can't search your vehicle?
Absurd.
When you can provide a title to the lands and structures to that property, then you can make the rules on it, until that point, your access to it is controlled by the owner.
No one is forcing an employee to accept a job where they feel that their rights are being violated, or that their life is in danger as a result of the workplace policies, so there are no rights violations here. If you are not in agreement on the way a property owner exercises their rights, then don't enter their property...you don't have a right to be on it to begin with.
You are demanding a non-existent right...the right to be on someone else's property on your terms and against theirs.
You simply don't have that right.
Loss prevention programs can include search of the employee, or any containers in the employees possession when exiting an area containing property, but not the vehicle, wnless there is probable cause.
"No one is forcing an employee to accept a job where they feel that their rights are being violated, or that their life is in danger as a result of the workplace policies, so there are no rights violations here."
That nonsense went out beginning with old common law. Biblically, violating anyone's rights was never permitted by God. Around the beginning of the 19th century, the States and the feds began to protect the rights of employees against arbitrary rights violations made possible by the employer's advantage of soverenty over the operation. Since the govm't fundamental justification for existence is to protect rights, their action on behalf of anyone whose right is being infringed w/o sufficient justification is proper.
"You are demanding a non-existent right...the right to be on someone else's property on your terms and against theirs."
Ridiculous. Whose name appears on the vehicle title?