HPF Subframe Reinforcement Plates
This subframe reinforcement kit for the E46 M3 includes all the components you'll need to stiffen your rear subframe to protect it from tearing apart under high horsepower applications. We recommend this kit for all E46 M3's. The HPF kit is the thickest kit on the market using 1/10" thick steel and reinforces the rear subframe mounting points in the unibody. It must be installed by a professional welder or fabricator. Requires grinding, metal cutting, welding and major component disassembly and assembly.