I never thought it was a good idea. From an officer safety standpoint, if you’re right handed, your gun is right there close to the prisoner sitting beside you. I wouldn’t want to be driving down the road and have to fight with a prisoner trying to get my gun at the same time.
My dad is a state trooper and I asked him if the situation ever presented itself, what they should do. He said they get trained for that in patrol school. I bet that’s pretty intense!