Hack, That is a very big request. Seems that at 11pm you wouldn't be able to get the visual effect you are really looking for anyway. Kinda hard to see at night. Anyway, there are some exotic car rental places around, but I've never seen a Cobra offered. Insurance is the key factor here, probably. I certainly wouldn't let some Valet Jockey behind the wheel of my car. As a matter of fact, there has only been three others that have driven my car besides me. If you were someone I knew, and had a $45K
cash refundable deposit, I might consider renting it out, but nothing short of that. Maybe you can find a car dealer that has one for sale that would consider renting it for the day.
P.S. If you plan on drinking booze at your wedding, I wouldn't rent it at all.
P.S.S. Find a nice 57 Chevy convertable to use. It has a huge back seat for you and your bride that is multi purpose
P.S.S.S. Congratulations on your soon to be numptuals.