DETROIT – Higher taxes on wealthy Americans, who typically buy Bentley cars, aren’t expected to have an adverse effect on the British auto maker, says a high-level executive.

“It’s a question of confidence and not money,” says Christophe Georges, president and chief operating officer of Bentley Motors, “and confidence has been up over the last two years.”

Georges says the luxury marque’s customers tend to own their own businesses and are less vulnerable to shifting economic winds.

Bentley chooses the North American International Auto Show here for the world premiere of the ’14 Continental GT Speed Convertible, billed as the world’s fastest convertible achieving 202 mph (325 km/h).

Powered by a 6.0L twin-turbocharged engine generating 616 hp, the car goes on sale in July. Price: $235,000.

North America, chiefly the U.S., is Bentley’s largest market. Sales last year in the region rose 22% to 2,253 units from 2,021 in 2011, Georges reports. Overall global deliveries also climbed 22% to 8,510 in 2012 from 7,003 prior-year.

Bentley has 177 dealers worldwide, including 43 in the U.S. and four in Canada. U.S. dealers will be added this year in Edison, NJ; Charlotte, NC; and the San Francisco Bay area, Georges says. Prices of its model lineup range from $174,000 to $296,000.