Whiteline Rear Essential Vehicle Kit (86/BRZ)Fitment Guide: 86 BRZ, 12 21 Product Description By matching key bushing, alignment and geometry products into one solution, Whiteline Essential Kits provide bang for your buck handling upgrades that simply Activate More Grip. Essentials include Whiteline rear differential and subframe insert positive traction kits, combined with low compliance control and trailing arm bushings for a more positive feel from the rear end during cornering and dialled in