Above floor pan, driver side
2004 Coupe -- I started getting some type of oil on my driveway a couple weeks ago, thought I had an oil leak. Checked dip stick, and it actually seems to be slightly over-filled, if anything? So jacked up the car and looked up under it, saw some oil on the transmission oil pan, but wasn't dripping. What was dripping was this little rubber valve(?) located above and to the left of the trans box. Was hard to tell exactly where it was, but I know it was dripping (right on my forehead, even) and did my best to get a picture of it. Also collected some of the fluid dripping from it in a cut-in-half beer can - it seems too thin and clear to be motor oil; kind of resembles to me the pentosin power steering fluid, but to my knowledge this is nowhere near the PS line.

Does anyone know what I'm looking at? I scoured the service manual for hours but couldn't find any clues (doesn't help that it's >3000 pages...) Is there supposed to be a hose attached there? Any help is appreciated!