What's The Most Popular Kia In America? Hint: Not The K900

America’s midsize sedan market is fading fast. Sales are down 12 percent this year, and the cars that operate farthest from the top of the leaderboard are the cars that are fading fastest: the Mazda 6, Volkswagen Passat, dying Chrysler 200, and the Kia Optima.

U.S. sales of the Kia Optima, the best-selling Kia in America in each of the last four years, are down 25 percent through the first ten months of 2016, a loss of more than four Optima sales for the average Kia dealer per month.

The Optima, therefore, is no longer the most popular Kia in America.

Launched in 2009 in the midst of a global recession, U.S. sales of the Kia Soul have been on the rise ever since. Sales more than doubled in 2010, jumped another 52 percent in 2011, and increased a further 13 percent in 2012 before Kia squeaked out a 2 percent gain in 2013 as the first-generation model neared the end of its lifespan. The launch of a new Soul for 2014 produced another huge improvement: year-over-year volume jumped 23 percent.

Kia reported a modest 1-percent uptick in calendar year 2015, including a 17-percent surge in the final five months of 2015 and an all-time best of 17,108 sales in August 2015 — a record that still stands.

In part because of an inability to match that second-half pace in 2016, coinciding with the overall market’s slowdown, Soul volume is off last year’s pace by 3 percent through the end of October. But Kia has already sold more Souls in 2016’s first ten months than in any full calendar year prior to 2014.

And the Soul, initially thought to be an oddball boxy niche-filler that would embarrass the Nissan Cube and send the Scion xB on its merry way, is now the best-selling Kia in America.

For pragmatic car buyer who wants a flexible and affordable package, there’s not much to complain about. Kia has progressively made the Soul better and better. A turbocharged Soul just debuted at the LA auto show, addressing one standout complaint regarding a dearth of power. But a few characteristics have remained constant since 2009: big league space and plenty of features inside, tidy dimensions outside, and reasonable MSRPs regardless of trim level.

You’re no longer surprised to see one. You’re not surprised to hear that your coworker can’t decide between a Soul and a Civic (“I think I want to sit up high”) or a Soul and a Crosstrek (“Do I need all-wheel drive?”) or a Soul and an Encore (“They both have a lot of features”). Incidentally, even without an all-wheel-drive option, the Soul, America’s 31-best-selling vehicle, outsells all subcompact crossovers.

Of course, part of the credit (or the blame) for turning the Soul into Kia’s most popular model belongs to the Optima and Sorento. Optima sales are projected to fall to a five-year low in 2016. The Sorento, which has moved upmarket since last topping Kia’s U.S. sales charts in 2011, is down marginally this year compared with 2015 and is off its 2011 peak by 15 percent. Combine these downturns with the Soul’s consistent success, and the stars have realigned.

Regardless of its precise positioning in the Kia hierarchy, the Soul that done brung the funk eight years ago is a downright mainstream option now. By the end of 2017, more than 1 million Souls will have been sold in the United States.

Timothy Cain is the founder of GoodCarBadCar.net, which obsesses over the free and frequent publication of U.S. and Canadian auto sales figures. Follow on Twitter @goodcarbadcar and on Facebook.