Before assigning a comment a label as "spurrious", you might actually look into it. So are you familiar with Tennessee law regarding sales tax on new cars? If not, you are speculating.
So you "wish" I'd looked into it.
I don't claim to be correct. But I do claim to have looked into it.
I read the proposed california bill that would have changed it. I read about the legislator that felt Tesla had benefited more than she thought fair, so she actively fought the bill. I read about how the bill changed. Then I checked with Tesla sales.
The system makes no sense. I don't argue that either.
There is idiocy in the California system that taxes out of state cars. They won't register the car and issue a tag despite taking the money.
There is idiocy in a Tennessee system that doesn't recognize another state has taxed a new car first, and poached the money that should belong to Tennessee. They want the tax or they apparently won't issue the tag.
I recognize governmental idiocy. I watch the news. I appreciate it more each day.
I really don't want to spend an extra $6187.50 to find out if you are right and the Internet and Tesla sales are wrong. So I'll just let them deliver my car and I'll skip the California vacation. And I'll warn others.
You are free to make your wishes. You are free to claim your knowledge is superior based on "probably encountering more situations like this than the rest of you", despite not having checked. I think you do the reader a real disservice offering advice unless it is confirmed correct for every state.
As for me, it is now moot. My Tesla is to be delivered on Monday. And mine will be taxed exactly once.