my 8 yr old daughter wants to sit up front in my 98 e320 4matic, i have the babysmart system that detects a booster seat, but she no longer needs one, i have seen transponders from the booster seats for sale on ebay, just tape them down on the seat and the passenger airbag goes off right? does anyone know of any other way to do this? where would i get a booster seat with the babysmart feature besides the dealer, also anyone know where else i can get the transponders?