Why are the Chinese buying fewer cars?

If you're selling Cadillacs in China, it helps that the US president is driven around in one.

Cao Chenyi, the boss of a Cadillac dealership near Shanghai, told me that customers know that Donald Trump's presidential limousine is made by the US carmaker. He says they like the prestige.

But Mr Cao's had a bad year. Demand dropped 30% in 2018. He's had to shut five of the 11 dealerships his family business owned. Almost half, gone.

"The sales on every new vehicle is causing us to lose money. Basically the more we sell the more we lose," he says.

Loss leaders are painful. Mr Cao has been forced to shift excess stock, and quickly. The red Cadillac he drove me around in is currently on sale at half price.