One thing I'm doing for my December solo trip is the following:
I'm getting two one-way car rentals from Alamo.
I'll arrive 1pm on a Wednesday. I'll pick up a compact car from Alamo at the airport. $26.03 all taxes and fees.
From the airport, I'll head to Universal Studios until closing, then I'll stop off at Wal-Mart or Publix and pick up a few essentials, then off to check into my Disney resort.
The next morning early, I'll drop the car off with the valet at the Dolphin and head for the Studios. (Some say just telling the valet to check the car in upon opening is sufficient, others say you may need to go to the desk once it opens at 9am)
The day before my return home, I'll be at Epcot. I'll swing by the Dolphin Alamo rental desk before they close at 4pm and pick up my rental keys and paperwork for my return trip. ($32.51 all taxes and fees) I'll then head back to Epcot for dinner and Illuminations. After that is over, I'll stop by the Dolphin again and have the valet get my car from the lot and head to my resort.
The next morning, I'll load my stuff into the rental car after checking out and drive over to Universal and spend time until about 3pm at Universal, then head for the airport returning my car.
So for a price in between Mears and a towncar, I get two trips over to Universal, an unlimited grocery stop, and even a stop at Belz outlet if I wish. I'm also not paying for days I don't need on a rental car.
Carol