A vehicle occupant sensing system adapted for detecting a condition of a vehicle seat assembly including at least one emitter and at least one sensor disposed spaced relative to the emitter. The sensor is operable to detect relative distance between the emitter and the sensor to thereby detect the condition of the vehicle seat assembly. The vehicle occupant sensing system also includes at least one sensor assembly having a base and an upper slide member moveable toward and away from the base. The upper slide member includes at least one interference member that generates an interference fit between the emitter and the interference member to thereby securely mount the emitter to the upper slide member. The vehicle occupant sensing system may be employed in a vehicle seat to detect a condition of the vehicle seat.