Correct, and his post was about insuring cars registered in Montana but are located elsewhere, which is a valid concern.
I was simply stating it's possible and actually not too uncommon to have registration and insurance in two different states, but involves extra hoops to jump through and some risk. In other words, it's probably best and easiest just to suck it up and register the car where it's actually located and pay your taxes, which anyone buying six figure sports cars should have no problem affording.