About the nutinserts, They come in 2 to 3 different depth sizes. For different thickness material's. Maybe that's why they lost there grip? Try this website http://www.mcmastercarr.com . Search nut insert, you'll be surprised from the different assortment. I use the knurled nut rivet. If the hole in the panel goes through the body and into the interior of the car, get the knurled ones with the pvc seal. That will keep water from penetrating through.