Detroit Speed - Rear Speed Kit 3 Single Adjustable Shocks4) The Detroit Speed Fox Body Mustang Adjustable Track Bar Kit adds a critical link to keep the rear axle stable during hard cornering. The factory 4 link is completely ineffective at locating the axle side to side as the suspension arms travel vertically. The addition of a Detroit Speed Track Bar to the Fox Body Platform will prevent the axle from wandering unpredictably. The track bar connects the rear axle to the chassis of the vehicle, which helps