[arijun]

What happens when they sell the car in a country that drives on the other side of the road? They would have to move everything around.

[chongli]

They could design the fuel tank to be symmetrical about the axis parallel to the car’s axels. This would let it be flipped during installation at the factory to have the refueling port facing either side. Then the only difference would be the body panel and little door that covers the gas cap.

[sitharus]

Many (mostly European and North American) manufacturers can’t even be bothered flipping the indicator and light controls around, there’s no way they’d flip the whole fuel tank.

[kube-system]

They could but there are downstream packaging compromises that would cause. It is easier to design the vehicle without imposing that design constraint on yourself

[aryonoco]

They don’t. It stays on the same side as it was. They don’t move the bonnet opening lever or the indicator stalk either.

[anigbrowl]

If they can switch the steering wheel and all the other stuff around they can switch the orientation of the tank.