What year/model is your car?
The BabySmart system works by the seat alerting the car of it's location, and the car shuts off the passenger airbag.
The transponder is located inside the car seat, and there is no way for you to access it.
The front passenger seat has the "second half" of the device.
Unless your car is an SLK or SL, put the kids in the rear and don't use the BabySmart.
1998 C230 "Black Betty"