I had one in my powerstroke that mounted up by the visors, but I actually had head room in that lol. May be better off to get the ones that attach to the back of the head rests.
yeah they make them, just do a google seach for vehicle mounted gun locks or gun racks. there are places that sell the ones that are used in patrol cars and suvs, some of them use the over head mounts in the back of the suvs.