Rider Alert

This is a heads up on a minor incident yesterday.
I was out on Lake Washington Blvd yesterday just south of the Mt. Baker Crew house and was hit by an object thrown by someone standing up through the sunroof of a car. The car was traveling in the opposite direction, north. I didn't get the license plate or even much of a description of the car (cream colored Japanese car?) It was so quick and unexpected. The guy who threw the object I believe was Caucasian, dark hair and probably 20 something years old. I turned around to see if the car might pull off in one of the various parking lots but they were gone. Along the way, I came across another rider who also had something thrown at him (he said it was a golf ball) which hit his bike. Today, a day later, my arm is still pretty sore. I feel lucky that it didn't hit my face. Hopefully, this is an isolated incident and this will be the end of it.