major oil leak
 

Ok so I have a 98 a6 2.8l, I work on the road so my car sits for a week at a time, I came home to a giant puddle of oil under my car... the temp outside was -10 give or take a few degrees for a couple days while I was gone. I checked my dipstick, it was completely dry... I added 5 quarts of oil and no drips or anything... but when I start the car, oil pours out in a steady stream from somewhere above the oil filter.. I tried using a mirror and flashlight to see up in there but for the love of god I cant see anything..

So I'd like to know if there is a small oil line up there that could have cracked, or could it be the whole filter assembly itself that cracked, and how hard is it to replace?