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.

 

To be honest I've seen them only on Chevrolet and Buick. Don't remember seeing them on Olds and Pontiac.

 

My 71 has those. I have removed them, as I'm working on the interior. I can't find them at the moment or I would have posted a picture. At first glance, they don't look factory. No logo or official markings etc.

My build sheet doesn't list them specificly, but it shows the following:

AK1 Dlx lap belts
A39 lap belts F&R

Box # 67 (seat belts) on the sheet says: 52-52

 

I have a few sets with the original GM packaging. I'll check to see what date is on it but IIRC they were around as early as the late sixties definitely 1970