LP Wheel Group is known as a company as an enthusiasts for its line of Chevrolet and Ford emblems studded with multicolored Swarovski crystals. For the annual Specialty Equipment Market Association trade show Wheel Group decided to create something several degrees more elaborate, and around 1,250 times more expensive: a diamond-festooned, 18-karat white-gold shift knob, priced at $150,000.

“I wanted people to feel luxury in the palm of their hand,” said Mr. Lee, whose company is based in Las Vegas, a hotbed of America’s high-end car culture. “People wear jewelry in their car, so I came up with the idea that the car should wear jewelry, too.”

Given the small number of consumers who can afford such opulence, Mr. Lee chose to design the shift knob for a commensurately pricey vehicle. “For the past couple of years, the most popular car for the big dogs has been the Bentley Continental GT,” he said, referring to a model with a suggested retail price of about $165,000.

Mr. Lee estimated that the ultra-blingy shift knob took 100 hours of labor to complete. It was finished just in time for the trade show, where it was displayed in a glass museum case, watched over by a model in an audaciously short dress. “Everybody’s jaw was dropping at how expensive it was,” Mr. Lee said.