My k+n came with 2 ducts something like 2" or 2.5", have a look at motorsports suppliers or Ebay for cold air feeds or brake cooling duct tube and just cable tie them from the bottom right of the front grill and direct the ends at the filter as close as possible

I was looking at the Golf tGTis back when I was also looking at STs, doubt I would have kept one as long as the ST which I've had 11 years