Unfortunately, many of our rights are only guaranteed from government...not your employer. You can refuse the search, but they can also terminate you with no recourse. The 1st amendment guarantees us speech which is free from control by the government. Most large employers are now employing Social Media policies in which you can be fired for what you put on facebook, forums, websites, etc. on your own time with nothing to do with work. So much for free speech. They also have people who monitor the internet for such stuff. Big brother is watching.
"Big brother is watching" is right. Because this forum is public, I make sure not to post anything that could be remotely construed in the wrong way.
I encourage you NOT to go against company policy. I'm going to kind of call you out on this one, but another reason you shouldn't conceal at work because is you've posted this thread on a public forum and you list your City and State in your "location", which makes you less anonymous. Now I might get called out for being "paranoid," but I always choose to be on the safe side.
I had a similar problem one time. I spent a weekend creating a hidden compartment in my vehicle that no HR dweeb would have found in the course of a cursory search. I suggest you do that. A compartment small enough to hide a snub .38 would not be hard to create.
Tread lightly before you get too invested in a secret compartment, I've seen motor vehicle codes with anti secret compartment laws, more to compound the charges against drug runners but if it's worded right and an LEO finds it on your commute you may have some explaining to do.
I'd be writing your political representatives and state carry advocates and maybe even the NRA to lobby for the parking lot protection (assuming PA doesn't have it, I'm surprised nobody has chimed in yet), then you've got some legal protection if it's stored in the car. Also may want to see if "corporate" is in a state that has parking lot protection, and would consider changing their policies to meet that (no need to mention carry, the hunting cause is a good one, or even if competitive shooting is a hobby and it would make your fridays easier and put them in better standing) Also take a look at how many of the states the company does business in have such parking lot carry laws. Kind of like when states update a law and it takes cities time to comply, it might be worth getting the ball rolling if you can establish a precedent and provide a non-threatening cause; it's not that you want to carry at work where the anti's jump to shooting up the place, but you want to look out for the companies interests and update the policy to make your weekends more relaxing, afterall you'll show up on Monday more refreshed. It takes some serious diplomacy to do without sticking your neck on the chopping block, but in your position, I'd assume you have it.
As I have said before, no way I would sacrifice my own safety (and rights) based on some stupid company policy. I would carry anyways (likely in a kangaroo carry or something super deep cover) and if I ever had to use my gun and got fired, well, at least I'd live to find another job. Your other choice is to quit. Your commute seems excessive anyways, find something closer to home and the money you save on gas can buy more ammo and new guns!
People think it's just that easy to "find another job". It's not. Don't risk it in the first place. If you need your job, don't do anything to jeopardize it. That would be stupid. Just about every company has a "no weapons" clause in their rules. If you agree to work for them, then you agree to the rules. My company has the same no weapons rule too, so I choose to leave my weapon at home. I don't have a choice. It's not worth losing my job over. I cannot afford to be unemployed again. It almost ruined me the last time. Besides, future employers will ask why you left your last position....ummmm....because they found a gun in my vehicle? There goes your chances for any future employment too.
You could simply requested an exception in writing and state your reasons. That way, it doesn't necessitate them having to revamp the entire policy for the entire company (which may be much more of an uphill battle that you are less likely to win). Find out who is responsible for the policy, explain you have an hour plus commute through bad areas, and that you go places between work and home, and you also have a concealed carry permit that you completed training and background checks to get. The risk is if you ask and they say no, then you're on the radar screen so to speak. I took that chance with my employer and was fortunate in that I was granted said written exception.
I don't see anything referencing your rights in the parking lot. Thankfully the new Wisconsin CC law expressly denies any company the right to do anything to any employee with a CC permit who keeps their firearm in their vehicle.
It sounds like an addendum needs to be added the Pennsylvania law.
Everyone seems to be talking about if HR has the right to search the car. I don't think that's really the point. I think the question that first has to be answered is if PA is a right to hire state. If it IS then what HR has the right to do is irrelevant. That can ask to search your car and if you don't let them they can fire you and there's not a thing your going to be able to do in court. If PA ISN'T a right to hire state then you have a lot more wiggle room. Answer that question first and then go from there.