U.S. auto sales are about to surpass a dubious milestone.
If this year's blistering sales pace holds up, more than 17 million new cars and light trucks will be sold.
That would not only be an astonishing comeback from the low of around 10 million sold in 2009, when the Great Recession sent Chrysler and General Motors into a bankruptcy which Ford Motors escaped only by massive borrowing.
It would also be a feat rarely achieved in the history of America's car industry.
Even using the monthly annualized figures, which are more volatile, auto sales have only surpassed the 17-million run rate in a couple of scattered months in the mid-1980s; in most of the heady period from May of 1999 through June 2001; and sporadically during the heavy incentive-driven, loose financing era of late 2001 through mid-2006.
Source: St. Louis Federal Reserve
And it's a high water mark that for a time was thought perhaps out-of-reach for good: the U.S., post-recession, was said to be "entering a new era," evolving away from car-dominated transport; the love affair with the automobile had even possibly come to an end.
Auto sales shot back up to the 17 million mark last August for the first time since the recession. They have held above that level in four out of five months through July 2015, and if that pace holds this will either be the strongest or second-strongest full-year sales total on record, after 2000.
The distinction is dubious because of its rarity—and because of concerns that it might once again mark the peak of a broader economic cycle.
Adding to that worry: the return of super-loose auto financing, a flood of now-used high-quality vehicles entering the market, and possibly excessive dealership confidence.
Consider what is now the country's largest Lexus dealership: a 40-acre compound, which opened in July, about a 45-minute drive northwest of Chicago in Arlington Heights, Illinois.
It features not only a showroom and service center, but a 170,000-square-foot main building that "also has a movie theater, playground, massage chairs, gym, golf, putting green and a salon for haircuts, manicures, pedicures and more," according to local press.
Then there are the Audi dealers, "in the throes of a $1 billion building boom," which reportedly includes mega-dealer Carl Sewell's plans for a four-story Audi store with 275,000-square-feet of space just south of Houston, Texas.
"Drive down any thoroughfare in the U.S. and you will see multiple buildings, shiny and new, all prepared to meet the growing demand for vehicles," said "Fast Money" trader Brian Kelly in a recent market note.
Remember the McMansion? These, perhaps, are the "McDealerships."
The trouble, said Kelly, is that the American auto industry is not in the midst of a paradigm shift to a higher sales rate so much as a one-time event driven by pent-up demand and an aging vehicle fleet.
"This trend will end and those shiny buildings that are specifically designed only to be suitable for selling cars will become empty shrines to overcapacity," Kelly predicted.
Most industry executives disagree.
"Barring dramatic economy shocks, like a major recession, we think annual auto sales will likely be in the range of 16 to 20 million vehicles over the next fifteen years," said Jeff Schuster, senior vice president of automotive forecasting at LMC Automotive.
One industry insider added that his employee discounts, which were ratcheted up and then extended to the broader population in the dying gasps of the last sales boom, so far haven't budged much, which he takes as a positive sign.
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.
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.
"This is just the beginning for Berkshire Hathaway Automotive," said Buffett, who plans to buy even more dealerships.
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.