To get the ball rolling I will tell the tale of a colleague at a telephone exchange in the 70's. He was a nice chap, but a bit 'keeping up with the Jones' ish in his nature.:
He was a field engineer working in the area and garaged his van in Radlett. One day he came into work in his brand new Escort and parked it in the exchange car park to swap into his van. He used to complete his work in the field and call in to the exchange for lunch. After two or three days one of the other chaps who worked in the exchange decided to have a bit of a game and drained some coolant from his own car's radiator and then poured a little pool on the ground under the new Escort's engine. He repeated this action every day and said nothing. A week or so later the subject came in to tell us that he had left the Escort at the dealer for them to investigate and cure the strange leak which he had noticed over the last few days but which oddly never seemed to happen overnight at home in his garage!! I'll leave the rest to your imaginations!!
