The sunroof on my 98 SL2 makes a loud, repetative clicking noise when I bring it to the closed position. The click continues as long as I hold the switch to close. If I hold the switch in the "vent" position, the sunroof goes past the normal vent position and stops about half way to the full open position. I believe the problem started when my sunshade became partially detached and impeded the window from closing once. Since then, I've had the problem and I try to avoid it by bringing the window near the closed position, without making it go the entire way. Any ideas on what I should look for? I have the Chilton manual with an exploded view of the sunroof. Thanks in advance.