Came back to car with one of the flaps mysteriously open?

[S0G17]

I'm struggling to understand what happened here. I parked my car, left it overnight, came back to it in the morning and on the back, to the right of the reg plate there was a flap open that I didn't even know opened?

On the diagram for the car, it would be the little circle to the right of the area marked "K", it seems like some kind of filler cap and was just hanging off the car. I looked inside and couldn't spot anything so I just pushed it back in. Does anyone know firstly what it actually does and secondly what the reason could be for someone prying it open?

[Obsidian Estate]

The cap for the towing eye?

[sportse]

Might have popped open if it wasn’t put back securely and worked loose. 
 

there was an issue with recent Honda jazz models regularly losing towing eye covers as they’d drop off, it doesn’t seem to affect the Corolla. 

[TonyHSD]

Or when bumper is pushed inwards and these easily pop out. Sometimes when parking if you just touch something with car at low speeds you may not even notice it. 
 

[S0G17]

So the Corolla has 2 towing eye covers? One on the front and the back?

With what Tony said, it might be that someone fell into that specific area, it's a residential parking spot with no spaces infront or behind, more a row of bays. There's a pavement parallel to the spot so it could have been a careless child on a bike or something, who knows.

[TonyHSD]

1 hour ago, S0G17 said:

So the Corolla has 2 towing eye covers? One on the front and the back?

With what Tony said, it might be that someone fell into that specific area, it's a residential parking spot with no spaces infront or behind, more a row of bays. There's a pavement parallel to the spot so it could have been a careless child on a bike or something, who knows.

Possible. 
Good at least that you have it and pushed it back in.