The 14 says this
210.52(G)(1) Garages. In each attached garage and in each detached garage with electric power. The branch circuit supplying this receptacle(s) shall not supply outlets outside of the garage. At least one receptacle outlet shall be installed for each car space.
I see nothing that says how many circuits are required to serve these other than that the "vehicle/car" space receptacles are on a circuit that does not supply outlets "outside the garage".
I see nothing there that says it can't supply the GDO from the circuit supplying the vehicle spaces, although a strict reading may prevent you from picking up a jelly jar outside the door.
I also do not see anything saying the vehicle space receptacle actually needs to be adjacent to or in the vehicle space. There is also nothing about the accessibility of these receptacles.
I can see an installer putting a duplex on the back wall and saying the bottom receptacle is for space A and the top one is for space B. He might even put a quad in the ceiling and say he has one extra after the GDO is plugged in.
As Scalia used to say, the law is what it says.