AGENT 47 Sway Bar End Link Kit 2005-2009 Mustang. Is your swaybar neutralized? When you car is at rest, your sway bar should have no tension on it. If you have modified your suspension, or had a lot of work done on your car, you may have tension on your swaybar and not even know it, causing your car to react at less than optimal performance levels in turns. This end link attachment kit, allows you to make sure that your sway bar is un-torqued with no pre-loading, resting in a perfectly neutral position, the way it should be.