Another possibility is the addition of a StowAway 2 Cargo Carrier. You do have to consider it's effect on tongue weight, and keep within the limits of the rear hitch, but is is about the only way to add outside storage to a 5.0.
I added one to my 17B & carried around 100 lbs in it. I did move some stuff to the front interior storage (under the small dinette seats) to get the tongue weight back to normal.