Broken fuel filler cap

[Nads02]

My mk1 yaris randomly opens it's fuel cap. First thought I was victim to theft but no petrol was taken and happened again by the time I got to my destination. After closing it, I managed to prise it open very easily with my car key. I've noticed that it seems a metal piece on the fuel cap bent slightly. I've been thinking of bending it back to place but worried I might over do it and not be able to refuel again. I could just smash the fuel cap off but I'm worried someone would nick my petrol. Theft is really bad in my area, I've even had my old shoes stolen outside my front door before I was going to chuck it away, saw it on the cctv. I could drill a hole into the fuel cap and body of my car and padlock it, but not sure if it'll kill me because I know as a minimum that petrol is dangerous.

I'll add some pictures in a couple of minutes need to go to my car.

[Nads02]

[Nads02]

[g3org3y]

Sorry, I'm not sure I understand. The door randomly unlocks or opens?

Is the issue with the locking actuator or the opening mechanism/hinge?

[mikeyr]

If it keeps popping open then perhaps a magnet glued inside the opening (and a metal tab on the filler flap) would keep it from randomly coming loose?

As long as the filler flap is shut no one is going to try and open random car filler caps to steal petrol so guess all you need is for it to appear to be locked?

[mmm-five]

Really need to see the internal locking mechanism, as it may be gummed up and simply not going fully into it's locked position.

If there is no lock, and it's just spring-loaded, then it may need the spring/door replaced.

[Flibble]

I think they're spring loaded - there's a cable release by the driver's seat.

[Chris32345]

People rarely Syphon fuel out of the tank filler these days they just lay on the floor under the car and stab a hole in the tank
Much quicker and less likely to attract attention unlike being stood at the side of the car with a hose and pipe

[E-bmw]

On the vast majority it is virtually impossible due to "anti syphon pipework".

AKA pipe with an s-bend in it.