When im at about 60mph i noticed my spoiler shakes alot is this a common thing on scoobys or is there something wrong with it??

 

Mine doesn't shake at more than twice that.

What car, what spoiler, genuine or aftermarket?
Is the car shaking too?

 

03 blob sti better be genuine but havent checked tbh and the rest of the car is fine its just the top horizontal part of it. how can i tell if its genuine or aftermarket if theres no visable part codes or logos etc??

 

post a photo

 

Mine does it too, only a little bit but its the same car as yours.