are close to the entrance of the park. Epcot is the farthest away from the front of the park. I could understand in that instance bringing the
scooter closer to the entrance, but the other parks are better. The International Gateway at Epcot has scooters, too which is by World Showcase. It's easier getting a scooter there, but you have to be staying at the Boardwalk resort and the others along the waterway for that to make sense.
You may be finding yourself going against the traffic to be somewhat challenging bringing the scooter closer to the entrance. For the other three parks it will not make enough of a difference to do this for him. For MK it's on the way in at the right side.
You may save some time standing in line to get a scooter ahead of time, but it may be a hassle getting the scooter to him where the crowds can be at there worse getting into the park.
The scooter rentals are in the same place at the parks where strollers and wheelchairs are rented. I can tell you at Hollywood Studios it's the place looking like a gas station called Oscar's Service and it's to the riight as you enter. At Animal Kingdom it's called Garden Gates Gifts and it's to the right as you enter the park, but it's a little further in then the one at Hollywood Studios.
I don't have a map and it may be difficult to get those, but maybe someone will post.