Welcome to the Forum.
What modelyear is your car?
In the Weekend Mk1, left hand drive, the pollenfilter#2 is located right next to the throttle pedal, behind a black cover#3 .
It can be very difficult to remove the old and install a new one.
It toke me more than 2 hours the first time, right now, I change it in about 15-20 minutes.
With a sharp knife, I cut the edges round, and cut away ever thing that sticks out of the new filter, put some Teflon spray at the edges, bent it, and slowly push it in place...lying on my back in the footwell, using a strong torchlite as well...