generally from reading most wings-spoilers work at speeds most of us will never see!! those who track their cars or drive on the autobahn will get benefits for sure. my 2001 TT has a small "wing" on the very heavy trunk lid, said to have been added to keep the rear planted as the first TT's built without one experienced lift at speeds above 110 mph while changing lanes + turning. this took place in europe of course, several death + injures were reported before the recall for adding the rear spoiler