It's the size on my convertible tire now... Can't speak for the sedan or coupe, but you can check your tire... And, as mentioned, you can fit afull size spare on the sedan (maybe coupe, I can just vouch for sedan)...
As for the cost... Dealer has it at $200+. It's a specialty item.... $110 seems reasonable considering you need it to not explode when driving yourself to a tire shop...