Cool story, and excellent detective work, Sally!

I love the fact that after investing in the meters, the scary wasp-coloured plastic pouches off Alibaba and all the rest of it, the owner then produced such a shoddy little photocopied Arial 24pt handmade notice.

And that it appeals to the driver's honesty, when by this point it's quite apparent that the issuer has themselves been highly dishonest.

They should have installed a change machine, giving 19 pound coins per 20 quid note, as well.