A vehicle immobilization system includes a detection element operable to detect a level of an intoxicant in a user's breath. A control module is operable to receive a signal from the detection element indicating the level of intoxicant in the user's breath, and to selectively restrict operation of a vehicle based on the level of intoxicant in the user's breath exceeding a threshold. A wireless relay is operable to replace a standard relay in the vehicle, and to wirelessly communicate with the control module such that the control module is operable to control the wireless relay to selectively restrict operation of the vehicle.