I think that the fact that the Ford dealer alone telling you to undo the glass to lower the top is enough proof to win in a small claims court. Now I don't know if you should or should not remove the glass when lowering the top, but the fact that the owner before you says that's what he did with the old top is also proof that even if your not suppose to do that, it won't damage the glass. So I think its the shops fault and they should just replace the glass anyways to keep a customer. It's kinda of a bad business move to only save $500 when they know they are probably wrong.