Sound like you have it figured out. Can't wait for the pics.

 

18" mini spare for 11-13' on ebay w/ $80 starting bid....

 

Just as a follow up and confirmation, the Drag 31 18 by 8 wheel with a 225/50/18 tire does indeed work and the height of the tire , fully inflated, matches the stock 19 inch Brembo wheels with maybe a 1/4 inch difference.
I am very satisfied and everything fits in the wheel well, I can now drive with abandon knowing I have a real spare.
I took some phone pictures, but they are just like and look exactly the same as previous posters in this and other forums, and it really is a hassle to put pictures on this forum so I am refraining from posting pics.
I am glad I found a local tire dealer to get this done, He was just as impressed as I was that the spare fit!!

 

Awesome.

 

Another solution:
http://www.modularfords.com/threads/...l-clear-Brembo

If you were going to pickup a set of Race Stars for quarter mile use anyway, you could keep one in the trunk as a spare.

 

Might be too late, but I have one 255/40/19 Pzero with 7k miles on for sale (cheap).

PM me if interested