Rear subframe failure is a common problem in the BMW E46, and the M3 model did not get factory sheetmetal rear subframe reinforcement. However, our BMW E46 subframe reinforcement kit can fix this common problem. Our 14 gauge subframe reinforcementsplates are made of steel and designed to reinforce the subframe mounting points on your BMW E46 by thickening the metal and distributing the load over a larger area. This reinforcement plate kit is also strongly recommended as a preventative maintenanceitem. Prevent cracks from forming and avoid costly repairs from common problems. Requires welding, professional installation is recommended. Contains the following: 1. Two 12mm x 1.5 bolts 2. Two front subframe mounting point Reinforcements 3. One Right rear subframe mounting point Reinforcement 4. One Left rear subframe mounting point Reinforcement 5. Two cross member spacers 6. Two square trunk block off plates Fitment: BMW E46 coupe & sedan. Requires minor modification to plates when installing on a BMW E46 convertible chassis.