I removed my front center seat with flip down back/armrest/storage console from the floor mounting studs. I got a new mount for a standard center seat, had nuts welded to it and bolted a lock box to it and mounted it back to the floor studs. I leave it unlocked with the key sticking in it while driving. I use an IWB holster with a metal spring belt clip. If I decide to remove the holster before or while driving I can remove the holster with firearm and place it inside the lock box through a webstrap secured inside the box. Once in the lock box if an emergency arises I can open the box and draw as fast as if from the hip while sitting in the seat. A gunsmith friend who is a competitive shooter really liked the setup when I showed it to him.
If stopped by the cops I usually have enough time to buckle up my seat belt, pull the IWB with pistol if in my belt, stow it and lock the box and pull the key before I find a place to stop. If I get stopped, once in the box and locked it ain't coming out. "I'm sorry officer, but the more you handle a loaded weapon the higher the risk of an accident. As long as it is locked up we're both safe."