I had a similar experience about 6 weeks ago, I was convinced i'd locked the car, but when i came out the next morning it was unlocked, parking change & sunglasses had been taken (which were not on show) and they had clearly been in the boot to have a look as that swung open as I drove away. I did ring Dulwich local police PSCO number to report it, as i thought they have a role to log local incidents like this, i left a message but no one came back to me. I wonder if the theives just walk up the roads and opportunistically try car handles to find any open ones?