Up to you. At my previous job, it wouldn't have mattered much, but at others, who knows. have you talked to your coworkers about carrying? Even if you aren't breaking any policy, you might still have to deal with issues that your coworkers might cause. Also, are you sure that policy doesn't prohibit firearms in the parking lot too? If it does, and you carry around co-workers, I suppose they could cause a stink about you having it in your car.