The MacPherson strut front suspension on a super beetle ties right into the body at the front fenders, being supprted only be sheet metal.  This can flex under high loads such as during hard cornering, hitting dips, etc.  This changes the geometry of the suspension as the flex happens.  This cross bar ties the two mounts together to make it much stronger, resulting in a firmer ride quality, as well as a noticeable difference in even how the car sounds under these stresses.  This bar is NOT a cure-all for shimmies and shakes, but it is an affordable upgrade to a stock suspension, or even one that has been upgraded.  Easy installation.  Some minor trimming or filing may be required to the bracket where it mounts up to the fender.