The American consumers who were stretching themselves to buy or lease a new car are starting to go missing from showrooms.

Rising interest rates and new-vehicle prices are squeezing shoppers with shaky credit and tight budgets out of the market. In the first two months of this year, sales were flat among the highest-rated borrowers, while deliveries to those with subprime scores slumped 9 percent, according to J.D. Power. The researcher's data highlights what is happening beneath the surface of a U.S. auto market in its second year of decline after a historic run of gains. Analysts believe automakers likely will report sales in March slowed to the most sluggish pace since Hurricane Harvey ravaged dealerships across the Texas Gulf Coast in August.

"There's not a bubble of subprime. But as interest rates rise, it's going to affect" those customers first, said Dan Mohnke, senior vice president of U.S. sales for Nissan Motor Co.

When the recession hit a decade ago, many Americans who had been affluent enough to buy new vehicles suffered investment and job losses that hurt their credit scores. During the recovery, lenders took chances on consumers with lower FICO scores, partly on the notion that borrowers prioritize car payments ahead of other expenses. Several financial companies started to tighten their standards more than a year ago.

"Subprime losses increased maybe to pre-recession levels a year or so ago," said David Goff, vice president of marketing for Westlake Financial Services in Los Angeles. "That caused you to require a little bit more from the subprime customer. And those people, instead of buying a new car, are switching over to a used car."

AutoNation Chief Executive Mike Jackson projects that even as new-vehicle sales slip again this year, the combined sales of new and nearly new ones will increase, meaning more business for the nation's largest dealership group and its peers.

Through February, sales of vehicles priced at $40,000 and up rose by 4 percent, J.D. Power said, while those priced at less than $20,000 fell by 19 percent.

"On a macro basis, we do see that the luxury side continues to grow; prices continue to go up there," said Henio Arcangeli Jr., Honda Motor's top U.S. sale executive. "But more in the mass market, pricing is staying firm, so I do say where the industry is probably leaking is on the bottom."