I know a picture would help . . technical issues. I'm going over my new to me 1999 911 C2 Cab. I noticed what appears to be a leak (oily looking) on the bottom surface of the rocker panel, just in front of the PS rear wheel, about an inch from the edge of wheel well. I removed the wheel well plastic cover and found a white plastic circular part (end of tube appearance) covered with a thin rubber disk. I assume it's a drain. The problem is I don't know where it runs to, I think it comes from inside the area were the top goes into. That's why the oily residue bothers me . . . the car does have a newly replaced top. I looked in the Bentley Manual and can't find a drain in that location . . . it shows one on the DS. Any help would be greatly appreciated! Larry