You would have to admit that passing the "looks white to me" test helps a lot in being culturally accepted as an American. You don't have to go very far to find counter examples. Even in this comment section people talk about "Asians" driving Tesla's - regardless of the fact they maybe second or third generation Americans.
The way you put it, it would seem odd to me to mention someone's ethnicity unless it was somehow relevant to the conversation.
Without context though my generous assumption is that when they say "Asian driving a Tesla" they mean "Asian-American driving a Tesla" and are lazy rather than racist.
I don't think they were being racist for what it's worth.
Putting it another way, if Elon Musk was born in South Africa and happened to be black, I doubt he'd so easily be given a pass as an American. Every article would start "South-african born entrepreneur Elon Musk..."
