And this from last Sunday:
looks strikingly similar to this from exactly a year ago:
It's not just the same car type, but the number plate is identical too! So I don't know what that means - either the plate was swapped over, or the bodywork has been switched or resprayed. I'm not sure what is least likely. But either way, there may not be quite as many different people independently parking odd cars in the same place on Sunday morning. And it would help to explain why they don't all turn up on the same day.