Another Mystery Solved...

So, the car is back and undamaged. Phew. Very weird story to go with it - but to cut a long story short, someone went to move a friend's car for them and instead of moving said friend's car, they moved mine. Using the key for their friend's car - they unlocked my car and started it up. Which is an encouraging testament to the safety level offered by my particular car manufacturer (the other car was the same make as mine - however a slightly different model).