Some years ago there was a light twin which landed at Staverton bringing people in for the Cheltenham races. When the pilot got back to it some time later. He found it was minus an engine. Turned out that the maintenance organistion on the field had done work on it at one stage and had never been paid. So they took their engine back!
I had a worrying moment once in Liverpool. Flew over from Dublin for our club's 'cross channel' check. Sitting in the terminal enjoying a cup of tea after surviving our epic journey across the Irish sea. Four Customs officers appeared and asked who was the pilot in command of that 172? Everyone pointed at me, the traitors. As I glumly accompanied the officers over the aircraft imagining my erstwhile companions making good their escape. I wondered what was going on. To my dismay they started going over it in detail.
Eventually with relief, I realised it was nothing more than a bit of training for some of the Customs officers. I then entered into the spirit of it showing them where and how you could hide things. Showing how inspection panels were easily removed etc. Thinking about it if you weren't too greedy there are plenty of places in a C172 to hide contraband.
But don't go to Liverpool, they're well trained now!