This is a very important step for the product to mount properly. This movie is perfect. These sound unbelievably good, especially for the price. Most offerings are nothing more than marketing hype enveloping an expensive yet vastly inferior product. They stay in place and lay nicely. I need it for special occasion and I don?t have time to return and get another one. The Lift of the Platform is Perfect! There is a plate to keep the rack from rattling, just tighten the u-bolt down as much as you need and the rack is silent. Thats why I bought several colors. ITS AWESOME.