Help understanding VA gun laws?

I'm a licensed CCW person with a legally purchased carry weapon and paperwork on file.

I'm trying to understand the law referring to storing a weapon in a vehicle in a locked, secure box while the car is on workplace property. I have read that an employer can prohibit weapons at work, but not in the car, assuming the workplace is not a CSB/behavioral health center. See this link: http://www.handgunlaw.us/states/virginia.pdf

To the contrary I have read where an employee can NOT prohibit storage in a locked box in a vehicle no matter the employer type. See this link: http://smartgunlaws.org/local-authority-to-regulate-firearms-in-virginia/#identifier_1_9150

I know there is a moral argument about carrying responsibly/secretively, despite an employer's rules...with the risk that your job is on the line. I also see that gun free zones are the low hanging fruit for those who wish to do harm. I would just like to know what, if any, legal ramifications there would be for having a weapon on premises (misdemeanor or felony) and what basis a search of said car would be legal.