Steeda's rear roll steer kit helps elimiate rear roll steer by correcting the bump steer geometry in the rear of IRS Cobra Mustangs. The design of the rear IRS (independent rear) suspension on '99-'04 Cobras is great for ride quality, but introduces bump steer characteristics like you see in the front suspension. The toe changes from bump steer produce unwanted rear toe changes resulting in unwanted steering inputs from the rear suspension. This produces adverse handling characteristics. This kit from Steeda allows you to fine tune rear bump steer geometry to improve steering response and handling balance.