Not in a "right to work" or "at will" state.Just because I've not heard of any civilian employer requiring that as a condition of continued employment doesn't mean it hasn't happened. But I would imagine there would be no shortage of pro bono lawyers who would love to make a name for themselves in a case like that.
My employer has a policy like the one I described. At their discretion they can ask to search my vehicle. I don't have to let them do it, but if I refuse I won't have a job.
If they find anything in it that violates their policy (including legal firearms) I won't have a job.
I know of 2 folks who have been fired under the policy. One had a car fire in the parking lot and his handgun was discovered in the wreckage.How would he even know you had a gun in your car? Why would you tell your employer or anyone else that you had a gun in your car?
Another's ex-wife set him up and then notified security that he had a firearm in the vehicle.
And while it hasn't happened where I work, in at least one case in OK, a company hired "gun-sniffing dogs" to come in and go through the lot. If the dog alerted on a vehicle then the employee had to open the vehicle and if there was a firearm in it they were fired. The fired employees challenged in court and lost, however the OK legislature passed a law to prevent a repeat performance.