Just so I remember to do this:  I checked the price of a car rental for the 4 days.  Typically, a convertible will cost over $700.  But if we try Priceline.com we might be able to get it for closer to $500 or less for the same period.

Since priceline reservations are not refundable, we can wait till we get closer to the date.  If it’s too expensive, a compact car is fine too.  No sense over spending.  A convertible does seem like just the car to drive in the Florida Keys with.