What states, ive been thru alot of em both east and west coast as well as the midwest and have never had an issue with the windshield mounted RVM.
I ripped one of them off while the cop was talking to me about a crack in it, said it was a obstruction of view, I invited him to look thru the front window from the driver seat, he agreed the RVM was a bigger obstruction of view then a vertical crack was. I ripped it off.
I find it funny that we let cops get away with whatever they want. You dont need a RVM, side views when adjusted right give you the same field of view that the hi mount RVM does.