Best thread I've found on this problem (and I've followed the steps and advice myself) is located at http://www.subaruoutback.org/forums/showthread.php?threadid=8005. This saved me a lot of money in repair costs!
BETTA WINDSCREENS CLIO 98/05
SUNROOF REPAIRS
Betta Windscreens Stockport Repairs to Renault Clio 98/05 Sunroof
Repair of a sunroof on a Renault clio can be carried out by anyone who likes a...
We had this problem with my daughter's Toyota Camry. In each corner of the sun roof there are drains, which can get plugged up with debris, which causes the drain gutter of the sun roof to overflow...
From under the hood, twist off the cover behind the headlight, then turn the collar that holds the bulb in place. Remove the bulb and replace it, reversing the above directions. DON'T TOUCH THE GLASS...