Well I do apologise

- a picture is worth 1,000 words (
as long as it is below 640x480 
).
And these are genuine Mazda alloys? Most alloy wheels have much bigger centre caps than that and seem to be a standard size (for example the centre caps from my wife's factory fit Audi wheels fit both types on aftermarket wheel fitted to our Bongo - different wheel on spare)
Here's our spare, and original spacesaver, you can see how big the centre cap is:
