The string of quality and design awards the company picked up this year, including North American Car of the Year at the Detroit auto show, didn't hurt either.
"Now, you don't have to go home and explain to your neighbor why you bought a Sonata instead of an Accord or a Camry," Zuchowski said.
On the downside, analysts note that Hyundai and Kia have relied heavily on incentives to move cars.
Whether the momentum lasts is a question Hyundai -- and many automakers -- are asking. Was the August sales surge a temporary, clunker-induced reprieve from almost two years of grief? Some auto dealers are already reporting a big drop-off in foot traffic into their showrooms since the program expired.
None of the automakers seems to think the 14 million annual sales rate implied by the month's results is a realistic indicator of the industry's health. But many see signs of a turnaround.
To cite one example: Ford said it sold more Ranger and F-150 pickup trucks, which posted year-over-year sales increases of 57% and 13%, respectively. Pickup sales are considered a positive sign for the construction industry because many of them are purchased by contractors.
"We'll see some drop-off in September," said Bob Carter, general manager of Toyota's U.S. sales division.
"But we're starting to see concrete signs of automotive recovery moving into the fourth quarter."