Mine has never opened on it's own when the keys were not in my pocket. back when I was undergoing Chemo it stayed on the key hook for 3 months and never opened once. But in my pocket is another story. I have even had the door to lock and the horn to beep. Most of the time these things occur when I am in a sitting, stooping or crouching position.
Cancer's a bitch! Enjoy life while you can! LIVE, LOVE, DRIVE...CAMARO!
The Bird is the word!