Quote Originally Posted by irving2008 View Post
Its not.... you still get suction... but it will reduce it...
Not even sure that is true Irving. Obviously it depends on wind direction and strength, but according to Bernouli, (can't remember spelling) wind blowing between the surfaces will cause a reduction of pressure on the underside, so in some instances will actually create negative lift (downforce). Anyway that is all academic - try to pass all responsibilty on to the installer!!! Good luck. G.