All the new GTI 16v mk2s with the ' SMALL ' bumpers that I either PDI'd or serviced had the ducting ( it slotted into the back of the spoiler and was secured in place by two screws and sprung metal screw retainers to the inner wheel arch trim/cover which had a cut-out .
( I think if you were to look at an GTI 8V (small bumper) inner arch trim you would see an outline of the section that is cut out on a 16V .)
They did away with the ducting when they brought out the big bumper models even though the gti spoiler had scoops ( though they were smaller and blanked off )
But your probably right..........they're as rare as rocking horse poop
