FredMan,
I'm on your side here, but a D.A. with some venom against gun owners might feel differently. He/she might even use the following approach:
"So, your defense is that when you're in your vehicle, you can't possibly be 'inside a financial institution,' is that correct?"
"Yes, sir, that's correct."
"Well, sir, if I were intent on robbing a bank, and were to drive my vehicle through the front window into the lobby, all the way up to the teller's window, would you say that I was 'inside a financial institution'?
It doesn't make it right; I was just cautioning against relying exclusively on the "vehicle != bank" defense. I'd still try to find out what your state's laws say, and see if there've been any rulings to establish case law.
Stay safe.
Jake.
P.S. Slacker, we've got a mall here which has a small building in the parking lot which houses an ATM. At least two people have been robbed there in the last eight years that I know of. There is also a drive-thru ATM about 20 blocks away. A few years ago, two cousins shotgunned a young college student there and used his card (which was still in the machine) to clean out his account.
Even though these instances did not occur in what one would call "bad parts of town," those types of places are not "safe" by any stretch of the imagination. It's what I call the "African watering hole" effect (I watch a lot of Discovery Channel). If there is not an exemption/exception built into the law, contact one of the CCW advocacy groups in your state. They will have a better idea whether it would be better to lobby for it or to keep quiet about it.