If you open the cover on the -S-, and look at about 3 o'clock around the hole there is a small button there. It is not depressed by anything when the cover or cap is closed, but you can depress it with your finger. Anybody know what it is?

 

that's the lock. it engages when your doors are locked. so you can't pop your tank.

 

Yep he's right ^^^. If you look on the chrome "cap" door, you can see the U-ring the "btton fits into to lock the fuel door. If you want to see that "button" in action, leave the cap door open and lock the car w/ the remote. That way you can see it work.

 

Is your MINI a girl or a boy?