I'm not sure where I might use it with my RV, except that it might save me getting out with a flashlight to check on something. In the fifties, when spotlights were still pretty common accessories on cars, they were useful for checking house numbers when trying to find the house hosting the party. That meant the right spot was more useful, but you needed spots on both sides (also for symmetry of style) and a spot operator riding shotgun.
By the 1960s we figured out the a high power handheld spot worked just as well, and was a lot cheaper.