Guys,
If you have a sunroof, take the time to search and find the pdf file for the sunroof TSB. It has been linked in the past and hioefully is still available.
If your sunroof is sticking and you are halfway mechanically inclined, you should attempt to disassemble the sunroof as per the TSB (it's not terribly hard), clean things up, and re-grease the parts. You may save yourself a couple grand for a couple hours work.
If your sunroof hasn't stuck, do the TSB anyway as preventive maintenance.
My sunroof was sticking and making the stripping noice and I did the TSB in my driveway. Everything is fine now and it cost me nothing.
Also, if your sunroof is stuck open, try pulling down on the wind deflector, as this may help it close.
HTH