I drive an ice cream van in a small town. Gas is about .50 cents a gallon more than it is 20 miles away in San Antonio. The van has a 35 gallon tank and gets about 10 miles per gallon. So, instead of driving a 20 miles to get gas and 20 miles back home, I decided to get a folding cargo carrier for my Prius since I have a tow hitch on it. I do Uber Eats, Doordash and Favor so I am in San Antonio at least 5 days a week and it made sense to buy gas there and haul it home. This will save me .50 cents a gallon. The two 5 gallon cans save me $5 combined every time I use them. I have used them twice so far. $10 saved. I went to Walmart and bought this..Hyper Tough Hitch-Mounted Folding Cargo Carrier for Automobiles with 1.25" and 2" Receivers - Walmart.com The carrier is not made to fold if you put it together with the 1.25" bar so I had to use the 2" bar. The hitch on my car is a 1.25" and I have a 2" adapter that I use whenever I hook a trailer to the car. Turns out the adapter added the extra length that allows the carrier to be folded up and is far enough away from the car that I could strap the gas cans to the carrier as pictured. I can open the hatch and use the back up cam without any problems. One thing I have noticed about cargo carriers on cars is that they eventually start to angle down, they are no longer perpendicular to the car like they should be. I think it is due to leverage and how much weight is put on the carrier. Since the gas cans are closer to the car that means less chance of stuff bending and causing the carrier to angle downward. There is a whole lot of play with this set up. I though there would be all kinds of noise when going down the road. Well, there is hardly any noise at all.
I think MikeDR means is it safe to carry thoses gas cans where they could make trouble if you're ever rear-ended. This was my first thought as well...
I know, I was just being silly. Well, it's safer than having the gas containers in the car. I did a search and there are plenty of hitches designed just to carry gas containers. This page deals with Jeeps...jeep gas cans at DuckDuckGo