Hi all, I've been following this forum for a while and it was always easy to find any answer to almost any issue I had in the past. Recently I bought a 2005 A6 3.2l. very low miles 43K, single owner, clean carfax usual drill ect. First time I noticed that something is leaking was when I parked it on the street 2 night in the row and there was a small puddle on the ground from where I left it the first night. Cross member mount part had some wetness to it. I had it checked out, and from what it looked like the fluid is saturating at the split between transmission and the transfer case. at first I thought it was gear oil, but it isnt, car is leaking ATF (greenish colored one).

Had the transfer case pulled and o-ring seal changed along with the transmission fluid flush with new fluid + pan gasket. and it is still leaking in that same spot.
my question is what seal could be leaking ATF? is there some kind of cavity? what seals back of the transmission from transfer case central diff bell housing?
here is the video of the leaky spot: IMG_1070 | Flickr - Photo Sharing!