What is a subframe and what functions does it serve?

A subframe is a structural component that mounts to the main body and supports the suspension, steering, and sometimes powertrain components. It provides a rigid mounting platform, isolates road and powertrain NVH from the body through rubber mounts, simplifies assembly by allowing suspension pre-assembly, and can be made from different materials than the body. Front subframes typically carry the front suspension and steering; rear subframes support the rear suspension and differential.