Yikes!! I never leave my cars running even in my own driveway. I also never leave the keys in my cars and keep them locked even in my locked garage. Sometimes I frustrate myself when working on my cars as I have to dig in my pockets with greasy hands to open the locked car doors. I'd rather have this habit of unconsciously removing the keys every time I exit the car than other bad habits. And I live in a very, very low crime area.
Hope you find it soon in good condition and this isn't some sick April fools joke.