I know it sounds like a stupid question, but I actually mean, how does the 2 studs that mount it to the car stay in place. I noticed a loose knocking sound when I went over bumps, popped the hood and looked in that area. I found that if I kicked the tire that the whole bolt,nut and collar jumped up and down. The collar is a part of the body? or is there another part underneith that bolts it to the car? zthanks for the info