Hello,
I have had this problem before.
First of all, you need to clean out the dirt in your sunroof housing.
As you have already discovered, there are two drains in the front. If they are clogged, you can use any regular cable that fits the drains to tunnel through them and unclog them. I used a regular T.V. cable. :)
The back drains are hard to reach from the sunroof side, so you can work from the other end of the drains which is located under the rear fenders. You should see some tubing sticking out. I used an air compressor to blow them out.
Good luck, and don't forget to dry your carpet and seats. :D
