You're stuck with the shuttle because all of the rentals were moved away from the airport a few years ago, but it does go pretty fast. You have to remember to allow at least an extra 45 minutes to an hour when you go home because you have to drop off the car and take the bus back to the airport. As far as the convertible, we rented one twice. The first time was in April and it was great. Top down, cruising the strip, taking videos was fun. The second time was July and we put the top down once and boiled alive. At night it wasn't much better. We drove around a little with the top down at night just because we could, but it wasn't particularly enjoyable like it was in April. Nice, cold air is what you want in June .