rear seat belt for 65 Dart wagon

[timbolia]

Hi, I need one seatbelt that clips to the eyelets under the rear seat of the 65 Dart wagon. Right now I can have my kids in the car or my wife and one kid. It would be nice if the whole family could have belts. I have one but I think it is a front belt that has bolt holes. I need one that just clips in.

Thanks
Tim