We used National car rental, located near the MK entrance. I called the day before and did most of the "paperwork" over the phone so picking up the car went very quickly. It was about $50 for 24 hours, and if I remember right when I called the front desk to ask about cab fare it was around 25 dollars each way. Plus, with the rental car we were able to stop at some of the tourist places in International drive, eat off property that night, and the next day had the car to check out a couple of places on disney property that we hadn't seen before. I think that Alamo is the name of the rental place now, you could probably get a coupon ahead of time as well. We only did this spur of the moment and had the ideal to check on rental cars after we found out how much cabs cost. After our day at Sea world we also went to Universal's City walk and checked it out. I don't remember how much parking cost, but for us it was worth being able to do a few extra things.