We've been proponents of proper rear suspensions for the Mustang since the early 90's when we started racing in SCCA road racing competition. The watts-link design has been around for well over 40 years, but the availability of it on the Ford platforms has been difficult at best unless you were willing to fabricate your own setup from scratch. Enter Fays2 Engineering, and their bolt-in kit available for the 2005-2014 Mustang. This kit is a bolt-in replacement for the panhard bar, and installs with common hand tools in around 2-3 hours. Engineered to take the suspension loads that a Mustang can put out while positively locating the rear axle in the proper position, this stout kit is in our opinion the best one available for your hard-earned money, and is what we use in the rear suspension of our own 2010 Mustang! On our 1993 SCCA race car, the watts-link suspension was good for over a 2 second drop in lap times over our panhard rod setup with NO other changes to the car, and comparable track conditions. By loading the chassis equally, the car will respond to left and right-handed corners equally, and roll center becomes fixed rather than varying like with the stock panhard rod arrangement. While this unit is at home on the open track, it will improve driveability as well just around town. It will help reduce the "skip" of the rear axle in corners, and will help to plant the rear wheels for earlier corner acceleration. Please note that if you have a convertible, you will need to order the adapter to allow clearance of the stock reinforcement on convertible cars. This only adds 30.00 to the cost of the kit when ordered at time of purchase.