I have a rear storage box on my
Scamp 16 that includes the spare tire. It is supported by 3 L brackets mounted to the bumper and also held in place by the spare. You can see it under Modifications/Preparing a 1991
Scamp. We have used one for 7 years.
It holds our water hose, electric cord, leveling blocks, a small tool kit. Below it are suspended two plastic fence posts. One post holds a long sewer hose; the other is used for miscellaneous items depending on the trip.
The box I mounted was $18 at Walmarts.