thatguitarguy -
Cool. It looks like you found the right size of pizza pan. My wheel has the center cap with four plastic "faux bolts" that hold the center cap on :
For my situation, I could drill holes in the faux-bolts and have screws coming *out* of the faux-bolts. The threads of the screws would then come out through the pizza pan and allow me to screw the pan down from the outside. I think that 4 points to hold it down would be good in my book. I also have the option of drilling a center hole through the center cap and having just one (strong!!!) center screw coming out (just like Christ is describing).
In your situation, I think your bolts are real because I don't see a center cap. But if you like my idea, you could figure out a way to swap out your bolts for double-threaded bolts that will allow you to mount plastic faux-bolts. But (there's always a but), in your situation, the faux-bolts may no longer be flush to the wheel,
.
CarloSW2