This is going to make me sound really dumb, but here goes....
A while ago I sold a pug 106 to a girl. Off she went to pick up her friends and go away for the weekend. I showed her how to work the petrol cap and all was fine. About 3 hours later she came back and was unhappy that the car wouldn't accept any fuel. The gague was showing empty, the light was on an sure enough when I took it to the petrol station I couldn't get the fuel in either! So, I gave her her money back and off she went. Never seen her since.
Anyway, I got fed up of this piece of s**t car looking at me everyday so I took it to my workshop who carry out all my repairs and left it there. They called me about 2 hours later to say that the car was full with petrol and it was the gague at fault...
FFS!