They need a search warrant or probable cause, so if you don't tell anyone then how are they to know. The Judicial branch has stopped interpreting the law and thinks they are the Legislation branch. Judges are confused with their actual duties.
The government does; not your employer. In Oklahoma you can be fired for not submitting to allow the employer to search your car.
Perhaps a disgruntled co-worker knows you have a gun and tells; or they start selecting random cars, or have dogs trained to sniff out guns. It doesn't matter, at the end of the day you will lose your job. it's not right but the way it is.
I too hope they overturn this as I will be working downtown soon and will probably refuse to ever work late if I can't protect myself.