How far can the sense of "self" expand?

I was talking to my wife today about how when use a fork, it seems like your mind expands your body to include the fork as part of your hand, e.g. what your mind perceives as part of the body is expandable. When you get into a car and start to drive around, it is like the car around you is an extension of your “self” and your mind almost thinks of it as a part of your body. For example, when people are in an accident it is “he hit me” more often than “his car hit my car”. Does this make sense?

So I’m wondering, what are the limitations? Does an airplane pilot think of the plane as an extension of himself in the same way I do about my car? How big would a vehicle need to get before the mind couldn’t keep up?