How would you really fix that though, if China builds manufacturing plants in Mexico, and then car dealers purchase their cars from there, placing higher tariffs on Mexico doesn't fix the issue, it just jacks up the cost of groceries, assuming the tariffs apply to all products and not just per company.

Is the idea to track the majority owners of every company and then tariff trade by company rather than where they are manufactured? What is the difference at the end of the day between a company moving manufacturing to Mexico to make the cars to avoid paying tariffs and a company making manufacturering plants for computers/phones in say China/India to get cheaper labor, and then sell the units back in the U.S.

We need a thorough revision of what the goals are and force the practices on all U.S. companies as well to make it ever workable long term.