That's not to say everyone is so bullish. AlixPartners, an industry consultant, has been cautioning the sales pace isn't sustainable and is about to top out. The firm expects U.S. auto sales to peak next year before falling below 15 million in 2019.
While that pace may seem quite low relative to the total U.S. population, keep in mind new sales are only about a third of the overall market, and the quality of the current vehicle fleet continues to improve.
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Indeed, sales of used vehicles, experiencing an echo boom from the strong recovery in new sales and leases, are expected to top 37 million units this year. Meantime, the average cars on the road today just hit a fresh high of eleven-and-a-half years, according to IHS Automotive.
And even if new car sales do manage to top the 17 million mark for an extended period, dealerships themselves still face several challenges.
The buy-direct model introduced by Tesla is a key one, currently working its way through a maze of state regulations that effectively require sales to go through dealers today. If the startup electric car maker gets its way, that may even revive efforts that Ford and General Motors themselves once led to sell direct to consumers. Volvo, the Swedish car maker now owned by China's Geely, has been selling cars this way for years.
Meantime, Tesla's Silicon Valley neighbors Apple and Google are also elbowing into the market. For now, their software runs inside traditional imported or Detroit-engineered vehicles. But it's not a stretch to suggest these consumer-product giants will one day sell the hardware too—and without an obvious need for existing dealer networks.
All this hasn't deterred Warren Buffett, however.
That billionaire's Berkshire Hathaway investment conglomerate bought the fifth-largest U.S. dealership network Van Tuyl Group, last October for an undisclosed sum.
"This is just the beginning for Berkshire Hathaway Automotive," said Buffett, who plans to buy even more dealerships.
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Racing legend Roger Penske, whose Penske Automotive Group operates the second-biggest dealer network, also remains upbeat—for now.
"I won't be around when [the sales pace] goes to probably 10 or 11 million," he told CNBC.
—CNBC's Phil Lebeau contributed reporting to this piece.