Let's start by pointing out that the responsible, law-abiding employees are the only ones who comply with company policies against having firearms locked in their vehicles in the company parking lot in the first place.
I hate to see government get involved in this.
It is unfortunate that there are employers who would penalize their law-abiding employees who wish to assume full responsibility provide for their own self-protection while in transit between home and work, and at all stops in between.
The companies certainly don't provide any protection for these employees during the commuting phase of each workday, and yet they think it's moral to deny the employee to provide for it himself.
If this is to be resolved legislatively, it must include the component that absolves the employer of any responsibility for any criminal incident which might involve one of these firearms locked in a vehicle in their parking lot.
A Keyboard and a .45: Employer Parking Lots and Firearms - A Poll