listing hold down?

[ltstreetrodzer]

Im new to the site and am looking for a few tips. I got a pair of bucket seats a while ago and when I pulled off what apeared to be old replacement covers, I found a piece of plastic down where the listing would go to hold down the seam that joins the insert and collar. I have never seen one before and am wondering if their is a male piece that was on the origional cover that snapped into it and if so where the heck can i find replacements? any info would be apriceated or if you just want to call me crazy and their was never anything that went in their thats ok too.