I won't lie I broke the lock mechanism on mine as well because I didn't know it locked with the car, I like someone else mentioned thought it was just stuck so I pushed a little harder and POP there went the locking mech

I haven't had any issues with the operation of my gas door, but my question is, why lock it at all if it's so easy to break open?

I've come the conclusion either I did, or the dealer did the first day he filled it up. Really not a big deal to me if my gas lid locks. Not worried about someone stealing my gas or putting sugar in my tank.