I took all the headrests off. nobody ever sits back there. Measure the diameter of the holes and look up "plastic grommets " or "plastic plugs" on ebay or amazon. https://www.widgetco.com/hole-plugs..._2OnGAiAYSF_Ylg7tLM9WeRinFRXLlCxoCPdAQAvD_BwE
Thanks so much. Best guess I can figure is about a ½".I took all the headrests off. nobody ever sits back there. Measure the diameter of the holes and look up "plastic grommets " or "plastic plugs" on ebay or amazon. https://www.widgetco.com/hole-plugs..._2OnGAiAYSF_Ylg7tLM9WeRinFRXLlCxoCPdAQAvD_BwE