Of course I did check there. There is no cutout for a key in the recess, but there is a small hole on one side that could be a receptacle for something small. But I believe you are correct, and the recess has no function in a MT car. I'm just curious about it and am looking for confirmation...
Good thought, but no, I don't believe that is applicable in a MT car. Also, the opening there will not accommodate a key. Very strange, although it will probably turn out to be a simple answer.