Hi Janice!
Thank you for visiting the Moms Panel!
There are two car rental locations at Walt Disney World Resort, and these are both operated by National/Alamo. Both of these car hire companies have offices at Orlando International Airport too, so if you have not already made your car hire reservation, perhaps you would consider choosing one of these companies, to make your car rental drop-off much easier.
The two locations at Walt Disney World are
1) The Car Care Center (near the Magic Kingdom) : Phone: (407) 824-3470
or
2) The Walt Disney World Dolphin Resort : Phone: (407) 934-4930
Both of these operate an efficient shuttle service which will collect you from, and return you to, your Walt Disney World Resort hotel, or a Walt Disney World theme park of your choice.
If you have any further questions, please come back and ask me - I would be happy to help you plan your magical vacation!