The way I heard this all those years ago was it would only work on the German stuff that was made with air actuated locking... VW, Audi etc.
It's not the air actuated locking that gives grief, it's the air actuated
not unlocking ... having gazed at the 'Empty Tank' light on my
pisspot er Passat Estate for some 20 miles I decided it would be a good strategy to refuel. ( I'm pretty bright with technical things like that

) . In a fit of petulance the wretched car then denied me access to the filler cap...

So, the RAC man then proceeded to oik out the panel and frig it, while I assisted by lavishing obscenities on the car, it's dealer, manufacturer, designer and anyone else that sprung to mind ..
The car was taken in to be fixed under warranty, they refused as it had been errr 'tampered with' ...
After a brief but intense exchange of views they decided to fix it anyway ...

BC