Help! Need a quick, clever jerry can carrying suggestion

Hey everyone - My son & I are just about to take off on a camping trip in Death Valley where the distances require auxiliary fuel. We're taking his 2001 XJ that has stock bumpers, no hitch, and factory roof rack rails. We're going to bring my big military plastic fuel cans from my JK, and realized last-minute (I know, duh) that the XJ has no way to mount them outside. We'd also love to put his 33" spare up on the roof, but in a pinch that can go inside, unlike the gas.

Our problem is we are seriously poor here and could scrape up maybe $50 max if we have to buy something. So my question is does anyone know of a cheap clever solution to securely mount the fuel cans on the roof, and hopefully also the spare? They have to stand upright. They are the Scepter military-only non-DOT 20L plastic jerry cans.

My idea would be go to the junk yard and pull a hitch, and borrow someones hitch mounted rack.

Mount spare on roof using two ratchet straps in an "X" shape. Place fuel cans to left and right of spare, and secure with single strap wrapping cans and spare all the way around. take another strap and secure cans across tops to roof rails. That's what my brain came up with; mileage may vary, if you feel that's safe.

Do you have any sort of recovery point?

I can lend you as many non leaking metal cans as you need that can safely go inside with you.

I'm in north OC.

Thank you all for the suggestions and offers to help. Very awesome!

Had a good ending. Remember I said I could maybe scrape $50 together… I went on Craigslist looking for roof baskets, and got a brand new one for $50. It's small but perfect for my needs. A kid with a street racer Subaru WRX had bought it ***purely for cosmetic reasons*** and decided he didn't like the look, and listed it for $50. Unbelievable.