Magnetic Attraction

My grandpa always used to say that you should wash bird droppings from your car as soon as possible to prevent the paint from being ruined.  So, when my car had been decorated with some droppings recently, I thought I'd better get to the car wash. We hadn't had any measurable rain for weeks, so it seemed like a good day to wash the car.  As you might expect, the minute I got out of the car wash, it started to rain!  We didn't get very much precipitation -- certainly not as much as we needed to quench the dry land and restore the brown, crinkly grass -- but enough to make spots on my freshly washed car.  I decided I could laugh that off, attributing my timing to Murphy's Law, so I drove around and parked my car in various locations as I did errands.  Following the last of my stops, I returned to my car only to find that it was not only rain spotted but now dotted with a fresh supply of bird droppings!  I'm not sure what the moral of this story is, but I now have several people asking me to wash their cars, just so it will rain.