Wow, I can't believe how much water you're getting. I had a water issue when I first picked up my '09 Tiguan back in the Spring. I had noticed water stains all over my interior headliner. It turned out the VW factory forgot to install the drains in the sunroof (i have the large sunroof option), and water was getting in and staying trapped. It sounds like you could have a similar issue? What's the dealer saying?