Hello,
Okay, take the carpet out from under the glove compartment, and feel around where it's coming from with the AC turned on. You should actually be able to see where the water is running (it's like a small stream

). A friend of mine had the same problem with his Passat. I don't remember exactly what it was caused by, but I know the problem was located under the glove compartment. It should be running down on the left side of the glove compartment, so check there.
Regards,
*Mario*