You don't want to keep it in the car. It'll vent fumes, make you sick, and eat up plastic surfaces (ethanol blends).

The original jerry cans were awesome, but killed off by the government. The new Rotopax setups are pretty sweet though!

 

Yeah, that makes sense! Thanks

What are some good ways to mount a can on the exterior?

 

Scepter fuel cans are the nicest fuel cans I have ever seen...owned.
They are the type of cans you hold onto.

That being said, I would not store them inside my vehicle.

https://civ.sceptermilitary.com/fuel_containers/

 

rear swinging jeep spare tire holder dealy...weld it to steel bumper.
have j can carrier

 

I think the best way to mount a jerry can/rotopax would be to a roof rack, or get a Gobi Rear ladder and mount it there. The hitch mount spare tire carriers are also an option, but they generally stick out way too far and aren't particularly light, from what I've heard. If you're into DIY, you could also mount the CRV rear spare mount into the hatch as others have done, and fabricate a jerry can holder to go on that.