The Special Interest Group on Component & Separate Technical Units (SIG-C&STU) proposes amendments to UN R159, UN R158, UN R151, and UN R166 to add Component and Separate Technical Unit approvals. For UN R159, the proposal introduces a universal functional block structure separating Detection, Control, and Human Machine Interface functions, with Component or Separate Technical Unit fulfilling Detection and Control as minimum requirements. The regulation is restructured into three parts: vehicles without approved Component or Separate Technical Unit, vehicles with approved Component or Separate Technical Unit, and Component or Separate Technical Unit specifications. UN R158 adds new devices for Rear-View Camera Systems and Detection Systems to Part I, with corresponding installation requirements in Part II. The group requests written comments within four weeks and plans submission to Working Party 29 in June 2026.