https://www.wired.com/story/china-conquers-mexican-automotive-market-and-the-us-is-worried/
State department hand wringing that China is going to use the US trade agreements as they were designed is 
I fully expect them to redo these with “except china” clauses.
you absolutely cannot do this
B-b-but what about the free market
Can you just keep it registered in mexico somehow? I live near the border and see mexican plates pretty often
Guess you can run into problems with the insurance, unless you get a Mexican insurer with a US coverage premium.