[bobcowan]

There's no problem with carrying a spare tire. A Mustang compact spare will fit most Cobras. Probably not those with extra large aftermarket brake kits.

The problem comes with changing the tire. Carrying a small jack and a lug wrench is not a big deal. But what do you do with the flat tire? It's huge! Where do you put it? If there's nothing in the trunk, you can let it hang out the back and bungee the lid down. If you've got the trunk full of other stuff, you're in trouble.