The Chinese state isn't selling cars under the cost of construction. The subsidies come in the form of cheap (increasingly nuclear) energy, publicly funded STEM/trade schools, and public health care. These socialized benefits reduce the real cost of living in China and grow the domestic consumer car market, along with lowering the per-unit production costs.

American car companies have long been hobbled by the obscene cost of employment benefits - high salaries to cover housing costs and student debts, high private insurance premiums, high administration overhead, the constant need to fund stock buybacks in order to keep the value of their stock-incentives up. The deal with the devil they cut with Truman - to make medical insurance a private tax write-off rather than a public good - combined with the enormous Reagan Era tax cuts and rapidly metasticizing private health industry administrative overhead, drives up the cost of each vehicle by thousands of dollars.

This sucks for the car companies, but is fucking awesome for the FIRE sector. And since 30% of the US GDP is tied up in financing, insurance, and real estate growth, our private automotive industry is effectively forced to subsidize their profits. That's what makes American cars so expensive relative to their East Asian peers.