[Jamesbo]

I bought a set of what I can only describe as rectangular black plastic cups that screw into the bottom a rear seat. They are made to hold the female end of the seatbelt tight and neat streached over the seat and held in place down at the bottom of the seat..

Does anyone know what year these things started being used? or an option code?

I don't want to use them in a 69 if they were introduced in 72.