I'm not so sure about that. Interstate trade is the sole domain of the federal government technically. If you are in Tennessee buying from a manufacturer in Detroit, I would think that federal laws would override state laws. Realistically, I'm not so sure how that works okay out.
It's been this way for decades without a serious challenge. Tesla has tried and largely failed to fight this (whatever else you might say about Tesla).
I think part of what Tesla failed at was opening direct buy dealerships in states, which becomes Intrastate commerce. They do allow you to direct buy, just not from the "showroom".
I suppose that understates it. They failed to get laws changed in a few red states. Considering how they can't produce vehicles fast enough, I don't know how much that even matters.