If you get the STi lip you can get the rubber skirt which is meant to protect the lip from minor damage. I have one which I yet to install, I ended up paying about $130 thru Japanparts which is pretty much just a rubber strip you could buy from Bunnings/Clark rubber with a bit of adhesive tap and a few screws

http://sti.subaru.com.au/SportsParts...d=0&part_id=81