Oops! I misread your original post, John. I thought you were already running the open air box, for which the stage 2 kit is designed (E7206).
If you're running Termis but sticking with the OE filter and lid, then a stage 1 kit would probably be more appropriate (E7106) e.g.
https://www.ebay.co.uk/itm/E7106-Car...-/202598732028