Obviously this isnt going to be for the exact same purpose but:
I have a 1993 Ford Fiesta 1.1, i have a book detailing how to work on it, one of the pictures shows how someboby had fitted an induction kit. Because the airfilter sits ontop of the carb (which is used for the single point fuel injection) you need a different type of induction filter than the normal cone. Anyway, below the airfilter there is a pipe which connectes to the carb from the oil filler cap. When fitting an induction kit a filter which looks identical to this one has to be fited onto the pointwhere the hose from the oil filler cap meets the carb.
Obviously an F1 car is more hi tech than my Fiesta
, but surely this filter must serve some sort of siliar purpose?
Could it be a filter for, say, a pnumatic system to lift the fuel flap?
Silence is golden when you don't know a good answer.