If Musk wants the US Congress to interfere, maybe he should sell liquor in the most lavish and expensive and functional "bottle case" ever conceived. But selling liquor in a car "case" might not be the best PR move. hehe.
In cases such as Wikard v Filburn and Raich v Gonzalez, the Supreme Court has held that Comgresses power to regulate extends to any activity which, in the aggregate, substantially effects interstate commerce. Such a test is trivially met by state laws forbidding the sale of automobiles directly from manufacturers to the public.
Have you read the Constitution?
Here is the 10th amendment.
The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.
If you read Article 1, Section 8, clause 3 you will find the Commerce Clause that grants Congress the following power.
To regulate Commerce with foreign Nations, and among the several States, and with the Indian Tribes;
When a manufacturer is in one state, and a customer is in another, the power to regulate business transactions between the two is clearly given to Congress by that clause. The 10th does not take that away. Therefore Congress should have power to regulate that commerce in any Constitutional way it wants.
(Note, your suggestion of selling liquor goes the wrong way. The 21st amendment expressly gives state laws supremacy in that case. But if no liquor is involved, then Congress should have authority.)
I am not a lawyer, but my lay understanding is that in this case the interpretation of the courts fits my reading of the text.
As bradleyjg points out, the Supreme Court copy of the constitution doesn't seem to include the tenth amendment. Between the commerce clause and the 14th amendment Congress can do pretty much whatever it wants.