There's definately no catch tank, it all feeds back into the engine. Unfortunately the car doesn't live with me, so fixing any issues tends to take a while! I'll hopefully get some photos this week or on the weekend. It seems to be only on that side of the engine, the other side looked clean, but without seeing it in front of me, I can't really remember. However, it's the area around that bolt that's leaking the most. That's where I was finding drips on the floor.