That's it basically.
Scared the sh*t out of me.
Was in the car on the phone (stationery) when there was a knock on the window. I jumped and said to the person on the other end of the phone to hang on a second (honestly thought it was a parking attendent or something).
There was no one there, nothing nearby, no other cars, no trees above me. Even checked in case a bird had dropped something, but, nothing at all.
Really shook me up, had to kind of laugh it off as being a "spook" to the woman on the phone, but, even she was a bit taken aback.
Will probably remain one of lifes mysteries