I had this when I first got my car, it was the water hoses to the turbos, leaks but not very noticeable until the engine / turbos are cooling then a wet mark at the end of the pipes could be seen.
sounds like same prob as mine Bos, pretty common for them to perish even on 03 plate. My advice to anyone who has not fitted new water hoses is to go remove a hose and see if it peels away by hand or better still just get em replaced!