Thank you for your input. Per the local MB Dealer (Seattle, Phil Smart Parts Dept) whom I visited with this morning, the P/N you provided does not apply to my car. Their Service Dept offered to open it up to check what's wrong, about 2 hours labour @ $115./hour. just to open up, mind you. Also told me they have never seen a sunroof repair for less than $1000. Hard to believe the poor quality (as in CHEAP) & poor part design in a "so-called" quality car; definitely not designed for durability.