Transferring gas from jerry can to car/truck is a hassle as you described.

Long ago, I purchased one of these boat fuel lines for transferring gas. As I have a pickup truck, I lift then let the 5 gallon jerry can sit on the corner of the front and side top rail of the truck box then put one end of the hose in the can and the other in the truck tank, squeeze the priming bulb a few times and the gas starts flowing via suction and gravity.

I have never timed a full 5 gallon transfer but don't think it takes much more then 8-10 minutes max. Sure saves a lot of work, especially when venturing far enough off-road where gas transfer needs to be done a couple of times in a day. Also these boat fuel lines are made out of much sturdier and reliable materials then the typical and gimmicky consumer fuel line transfer hoses and should last a lifetime.

This may not work for you unless you have somewhere on the car or something like a Workmate type table where you can place the gas can a bit higher then the car gas tank.