Very good points. Only strap it on when going off roadingNot a bad idea and non permanent you don't have it on all the time getting rusty.
I would do this before putting gas on the roof or in back directly exposed to a hit from a car.
Worst wreck I ever saw was a rear end at a light and the truck had a full Jerry can in the back tire.
I was going to do this but had a couple concerns:I've been thinking about this as well. It can be removed when not in use as well. The only thing with it is you have to remove the rear brake light when installed. Not sure how easy that would be.
M.A.S.S. Spare Tire Platform (STP) - American Adventure Lab