Ladders
I don't, cause I'm too heavy for the ones which are available. But if you are only 200 lbs or so, you can get one which collapses side to side (if you have a long, skinny place for it) or one which collapses top to bottom (short, wide, storage place).
Of course, if you have a ladder attached to the rear of the RV, its questionable why you need one. The built in will get you to the roof, and anything else, you probably won't need to get to until you get home (unless this IS your home, and then see the first paragraph).