Has strut insert been replaced?
 

I'm looking at the tops of my front struts, and it appears that the undercoating has been removed and "messed with" in the past. Is this a pretty sure sign that the struts have been previously replaced, or would this need to be done to change front end alignment, etc.? Or is this how they appear from the factory?

http://www.brown-house.net/~pbrown/9...hock%20Top.jpg

That looks original to me. As I understand it, the red dots you see are applied at the factory after torquing to spec. Seeing as the washer is folded over the nut with the red dot bridging the nut and washer, it looks like the strut has not been removed since it left the factory.