Green hailstones..

Parked in the shade, under a tree when there was a "thump" on the roof...couldn't see anything....then seconds later it happened again...

Got out, another "thump" - culprit unseen...waited a while and there it was again..

Aha.. caught you...mini-conker pods from above...

no wonder the parking spot was empty....and thank god they weren't full grown...