Just a little aside. I think the US automotive sales market is actually still slightly bigger than in China. China sells more new vehicles, but when you add in used vehicle sales the US auto market is slightly larger. For example, there were a combined 49.31 million vehicles sold in China while there were a combined 51.4 million vehicles sold in the US for 2023.
This won't last for long though, and I expect that in 2024 the total number of vehicles (new & used) will exceed that of those sold in the US based on growth rates.
I wanted to point this out because just looking at new vehicle sales hides how massive the US used vehicle market is. Estimates put the 2023 used vehicle market sales in the US at 35.9 million. To put that in perspective, that puts used vehicle sales in the US ahead of new vehicle sales in China (30.09 million) for 2023.
Also, this isn't meant as a US is better then China post, but just to put some perspective on the size of the auto markets in each country. With 1.2 billion plus people, eventually Chinese automotive sales will far eclipse those of the US. I think these numbers highlight how much growth potential there could still be.
Used car sales just tell you how often people change cars and how long cars are kept for. Suppose people decide to keep their cars for longer and used car sales decline?
But if you don't like [new vehicle sales] as a metric, you're better off looking at [total number of vehicles] to determine the size of the overall auto market. On that measure, it looks like China is slightly larger in terms of numbers.