You know, I thought about suggesting a rental car this morning on my way to work. If you want to go off Disney property during the day as well, you should definitely look into it. I know there's an
Alamo at the Walt Disney Car Care Center and another one at the Dolphin hotel (when I was there, this one didn't accept cash guarantees, only credit card, and the card has to be on the name of the main driver). I think there are other car rental companies at the Disney Car Center, but I'm not sure. I know you can set it up with the companies so that they'll come and take you to their location, and afterwards they'll drop you off at your hotel.
Just for you to have an idea, if the main driver is over 25 years of age, you can book an economy car for one day at the Alamo at the Disney Car Center for about US$ 95,00 (this includes two types of insurance and a GPS). If you add US$ 15,00 for parking at Universal and about US$ 10,00 for gas (I'm guessing here), It should run you around US$ 120,00, which is not a lot more than what you would spend for 2 taxi runs, with the benefit of having the car all day and being able to go to multiple locations on International Dr.
On another topic, I was at the Sleuth's mystery dinner show some 12 years ago. I had a lot of fun and enjoyed the food. Hopefully it hasn't changed and you'll enjoy yourselves there
Once again, hope this helps
