what are the fittings called that the bungees go thru
They are tarp grabbers, they are in 2 pieces and press together through the material, one has a spike and the other a hole. I get them from Northern tool in a 12 pack for about $7.
They work very well and I have yet to have any pull out on the vinyl that I use for the sprayshield. I have tried to pry them apart in hopes of reusing them when experimenting with placement but haven't had any success even with a gorilla bar and vice grips.
Bunj balls also work well but on the light duty ones you do need to double the knot to keep it from pulling through and they will get stretched out, I switched to the heavy dutys but they can be hard to put on and take off.