I placed mine in the toolbox on the drawbar. Didn't want the smell in the van and it is on the same side as the filler on the ute so can fill up at the same time without moving the van.
I've modified a 10 litre fuel container and made up a swing down bracket for it to sit up behind the rear wheels. didn't want to have it inside or on the A frame so was the best I could come up with at this stage.