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.
Nationally, 2018 was a very hard year for the car industry in China, the world's biggest car market.
Just over 22 million new cars were sold last year. But that's a near 6% drop on 2017. The first fall in two decades.
Inside Mr Cao's Cadillac showroom various models are side by side. An SUV at the back has a canoe on its roof rack.
I watched a group of three youngish men come in and sit down for the sales treatment. They didn't buy.
They didn't even have a good look inside the cars. Mr Cao thinks the main reason is a tax cut that has gone away.
"In 2018 the government cancelled the tax subsidy on car purchases, which was a shock to us," he says.
This benefit has been gradually wound down. Others think a credit squeeze has caused the demand for cars to drop.
After a decade of near doubling its debt - to almost 300% of China's GDP - 2018 was the year that the government tried to deal with the aftermath of a credit crisis. That crisis was centred on peer-to-peer lending, known as P2P.
P2P lenders offer loans to individuals from a pool of funds supplied by other individuals and other businesses, thereby cutting out banks.
Cars and houses
Economist Andy Xie says the previously increasing national debt kept demand high, particularly in the property and car sectors.
"Now the property market has tipped over, and it's affecting a lot of things," he says.
So why is property so important?
"Auto sales are highly correlated to property sales," Mr Xie says.
"When people buy property it seems they buy a car at the same time. So when the property market is not doing well the auto demand is down."
The collapse of many of the P2P lending platforms is thought to have had a significant impact on both house and car sales, because borrowed money was being used as down payments for both.
Mr Xie says the credit system "used to be lubricated by these guys" and suddenly that has stopped.
"They lent to people who could not pay back. [Borrowers] shifted their debt from one platform to another."
He tells me he's heard statistics suggesting one in four such borrowers "have no ability to pay back".
