Seat belts in NA

[Mikkels]

Hi My 1990 NA seatbelts do not have the little plastic button that is on modern seatbelts that stops the buckle sliding down the belt. Consequence is that the male part of the buckle thats on the door side belt slips down the belt and either gets jammed in the door preventing it closing or disappears into the 5th dimension and needs to be dug out every time.

Anybody solved this problem? Can you source the button thing and install on old belts.

Don