I've been playing with this armored car. It can withstand all types of gunfire and gets dented if it hits cars and walls. But it's very difficult to catch fire. I've been trying to destroy it for months and I can't. As you can see, it's pretty dented.
I don't know how no one's been talking about this armored car. Here's the map location. If you want to use fast travel, get off at the Sunshine Motel station, right in front of the Militech cluster. It's the only one of their cars with this electronic system in the rear. I zoomed in to make it easy to see. It's easy to identify from the other two there.
If you have any doubts when you find it, unload a full magazine of bullets into it and then come talk to me.