Well, We've been having a lot of rain lately and I've been unable to stop the leak, so I broke down and went to the dealer.
Turns out, the service rep told me the drainage tubes from the moonroof were all clogged up. That was causing the leaks. They cleaned out the drains. There was also a little corrosion where there was some wiring due to water exposure so they cleaned that up and sealed it. Total cost was about $300. Thanks to you all for your comments and suggestions!