And there's a simple solution that seems to elude everyone - have filler caps on both sides. There are cars like this already(although only the most extreme ones, I think the Veyron has two, I guess it would be too peasantly too run the hose over a million dollar car). I guess it makes the production slightly more complicated, but it solves the problem entirely.
A teenage friend of mine had a pickup truck that had two tanks connected to the two filler caps, which was interesting, almost aircraft like.
We're talking about a 70s beater pickup truck modified as only a 80s/90s teenager has spare time to modify, so I have no idea if this was normal for construction grade trucks or not.
The theory is he could operate his gas powered generator/welder or gas powered air compressor off one tank at a job site, and even if he ran it dry he could drive home on the other tank. There was also some manner of fuel transfer pump(s).
It was pretty common in trucks of that era. My father who -owns a construction company - has owned several of these. Never had any external devices, just used it as a "range extender".
And then you forget to fill both and you are stranded... :-D
A friend of mine in college had an ancient VW bug that had no fuel gauge, by design.
When it ran out of gas, you had to switch a foot pedal to the emergency tank, then you had maybe 10km to get to a Petrol Station before you were stranded.
My first car, we couldn't keep the gas gauge working reliably, so I had to reckon the mileage from the odometer to keep track of whether it needed to be filled. At least it did have dual gas tanks, so in the worst case, you'd notice the engine was chugging and trying to die, and have to flip the switch to the other tank in time.
Filling up both tanks kind of sucked, back when gas was $3.50-4.00/gallon.
Huh, interesting that having an emergency tank with some mechanism to switch between tanks was a cheaper/easier solution than just having a fuel gauge.
I would hate having to replace a rusty fuel filler neck that runs across the wrong side of the car and over the exhaust.
We should just go back to the 70s-era centre-mounted fillers behind the license plate holder. Those were great, until you got rear ended or it was frozen solid.
These were depopularized after the arrival of self-service gas stations due to modesty issues regarding drivers refueling themselves while wearing skirts or dresses.
