We recently lost the part of our center cap to our 93 DeVilles aluminum wheel. Replacements for these are expensive(dealer- $100.ea) and and hard to find used, especially if you need the gold script models.
The reason we lost ours and why they are hard to find is because the adhesive that bonds the ring and the plastic dome together becomes dry and allows the dome to become seperated.
I finally located a nice one from "Superior Hub Caps." When I got the new one I checked it out by applying pressure to the dome from the back side. With just the slightest pressure the dome popped out. If I had installed this as it was, it would have been lost also while driving in the not too distant future. I removed the three remaining caps on the car and found another on ready to seperate.I rebonded the caps and rings with an epoxy adhesive after thoroughly cleaning both surfaces.
If you have a DeVille with these style wheels, I SERIOUSLY RECOMMEND CHECKING YOUR CAPS FOR LOOSENESS. Youll be glad you did! Rob