I have an 06 R53. I replaced a serpentine belt and a blue ring fell out from my shock boot. What is it?

 

Believe it or not that is what is called a shipping block or at least half of it. That was installed the day the car was assembled. It was used to maintain the suspension travel when the car was chained down to the transport racks on the ships and on the trucks. That way it didn't bounce around. The original dealer should have removed them during prep, but it looks like they weren't. I would check the other corners. Also if the were in there the original owner must of suffered a terrible ride until they got smashed around. They acted as bump stops and didn't allow full suspension travel.

 

Thank you! I was getting worried. R53 runs and rides fine.

 

I cant believe it lasted up there that long.