Wow. You really don't understand what "core competency" means, do you?
Ok....what do you think of when someone says Toyota? I'm sure it's not tires, radios, or groceries.
Answer my question and you'll have the answer to yours.
To help you in the future:
Core - the central part of something or most significant element.
Compentency - something you or they are good at doing.
SO what is the central or most signficant thing that Toyota is good at doing?