Reflections work like they would in real life. Add your object. Then create a shape using the rectangle tool. Change the shapes x rotation 90 degrees so the object sites on the shape. Add the reflection to the shape not the object and the the rectangle shape will reflect the object. It work very cool. Hope this helps.
Reply me thanks x, First answer is just doing it manually, But Io I can not do it just to see how they do in the movie http://www.Pixelcorps.Tv/macbreak_studio047 I also turned around as he says (eyal shtark) but nothing, Looks dead.