Abstract: A motor vehicle carjacking defense apparatus comprises a double pole switch which actuates at least one solenoid controlling at least one valve which interconnects a nozzle to a pump connected to a pressurized tank containing a non-toxic and non-corrosive irritant. The switch also overrides the vehicles electric window system, the alarm system, and the air flow system simultaneously sealing the windows and the air flow system and energizing the alarm system. Alternatively, the switch located inside the vehicle actuates an infrared heat detector connected to said solenoid wherein upon actuation of the detector, the detector energizes the solenoid from an electrical power supply. A plurality of nozzles and infrared heat detectors are arrayed around the vehicle whereby when the detector is armed it detects the presence of a carjacker and causes a spray of a pressurized, non-toxic and non-corrosive irritant and smoke towards the would-be carjacker.