I received my 15" Vintage Halibrand Replica Wheels a couple weeks ago, did the 4 lug to 5 lug axel swap using Ford ranger axels for the rear, and mounted up the wheels. They look great. My question is what holds the center cap for the rear tires? If it let it, it will almost disappear in the center of the hole after the wheel is bolted on with the lug nuts. Using the spinner to pull it out does not allow me to get it super tight because it's starts spinning with the spinner. Is that all that's holding it in the wheel?

My car is a Mark 2 with 8.8 rear end, if that helps.
Thanks!
Mike

Pictures: http://www.prairieroad.com/cobra/february2012/