This is such a silly criticism, of course Tesla's share of the "EV Car" market is going to shrink as more companies sell EV cars. DUH! But that is a silly way to view things, Toyota was never compared on their share of the "Hybrid Car Market", because that is not a real thing, just as the "EV Car" market isn't really a thing, people buy cars and to the extent they cross shop they generally do so across drive trains.
Tesla's share of the overall Automotive market is growing and that is what matters.
The Model S is a tiny and irrelevant portion of Tesla's sales.
Tesla's share of the overall Automotive market is growing and that is what matters.
The Model S is a tiny and irrelevant portion of Tesla's sales.