I use a specialty safe that I've used for many years now with great success. I've tested it in many different conditions on multiple continents. I've never had a failure. The gun simply stays on me/ with me. So, it's universal for any vehicle I get in and also secure when I leave the vehicle. I've seen failures in many other systems. I do understand that many locals have locations that are restricted from civilian carry. I choose to either avoid those locations or make a special trip to them, and in some cases I merely conceal better.
I do not say any of this to attack anyone who uses a different method, and I'm eager to learn more about why some folks use vehicle-mounted options. I've just not come across a need yet personally.
I admit I am an old man who would be considered set in his ways and not necessarily open to change. But, I have been carrying a gun either personally or professionally since 1994 and have trained and for many of those years taught others in working in and around vehicles.