The reason you see them on the driver's side is because that's where the factory put the spare tire mounting bracket. That's the factory bracket directly below the hand of that married guy. You usually don't see them remaining on pickups. Most all of the beds I see have that bracket long gone. I honestly think you made the right call putting it on the passenger side. I'd say 90% of the time you are going to load/unload something small in to the bed it is going to be right behind the drivers door on your way to getting in or out of the truck. That's usually where I load cans of gas, or other stuff I don't want in the cab with me. Having a spare tire in the way kind of ruins that deal.