"The more expensive the car, the more dry the business," said Tommy Siu at the Causeway Bay showroom of Vin's Motors, the used-car dealership he founded two decades ago.
Sales of ultra-luxury cars have halved in the past two or three months, he said.
"A lot of bankers don't want to spend too much money for a car now. At this moment, they don't know if they'll have a big bonus."
With the highest proportion of billionaires in the world, according to a Boston Consulting Group report released in May, Hong Kong has enough buyers unaffected by market conditions to keep new sales going, said Bill Russo, a Beijing-based senior adviser at Booz & Company.
The new-car figures look better because of some short-term developments.
The release of the latest models from Ferrari and Lamborghini and the opening of the first Hong Kong showroom by McLaren - maker of the 592-horsepower MP4-12C carbon-fibre coupe - have given sales a bump.
Meantime, depressed demand in Europe means a bigger allocation of new cars for Hong Kong dealers.
There were 273 new Bentleys, Lamborghinis, Rolls Royces, Ferraris, Aston Martins and McLarens sold in the six months to June 30, up from 186 in the first half of last year, according to Englewood, Colorado-based IHS.
For these buyers, price isn't an issue and settling for second-hand is not an option, Russo said. "Used-car buyers are more price-sensitive and economic cycles will affect these shoppers more. They are paying for the cars with their income as opposed to their savings."
Hong Kong's economy eked out 0.4 per cent growth in the first quarter, the slowest since escaping the recession caused by the 2008 global credit crisis.
People shopping in the second-hand market are typically aspirational buyers who are more likely to sit it out rather than trade down when they can't afford the brand they want.
Vin's Siu said the drop in high-end customers who typically account for 30 per cent of turnover at his 300-lot business was the most important factor behind a 20 per cent drop in total sales.
- Bloomberg