Relates to requirements of motor vehicles

S 4164 requires most passenger vehicles (under 10,000 lbs gross weight) registered in New York and manufactured after July 1, 2027, to have a rear-seat detection system. The system must identify if a rear seat occupant is present (via seat belt latch and weight over 20 pounds) after the engine turns off, then provide a warning. This applies to standard passenger cars and SUVs but excludes motorcycles, commercial vehicles, and truck-trailer combinations. The bill takes effect 180 days after enactment, with a provision for automatic repeal if it conflicts with federal law.