Let's face it. Station wagons are no longer popular in the US. The segment that once ruled America's suburbs was first replaced by minivans and now crossovers. Wagons, meanwhile, are gone from the lineups of mainstream brands such as Ford, Chevrolet, and Dodge. There is one non-luxury brand, however, that not only sells a wagon but it also dominates the segment in the US. That would be Subaru and its long-running Outback. The only other wagons available in the US come from luxury brands, such as the Mercedes-Benz E-Class wagon, Volvo V60 and V90, Audi A4 Allroad, and upcoming A6 Allroad and RS 6 Avant. In other words, the Outback has the mainstream wagon segment all to itself.

According to J.D. Power, only 1.4 percent of all car sales in America last year were wagons. But as CNBC points out in a recently published piece about wagons with data from J.D. Power, the Subaru Outback made up 85.7 percent of wagon sales in the US, or 1.2 percent of wagon sales.

This means all of the above-mentioned luxury wagons are competing for just 0.2 percent of the wagon market. CNBC's video segment does not specifically delve into how or why the Outback became so immensely popular, but it does mention one critical element: "part wagon, part crossover."

Remember, the Outback is, essentially, a jacked-up wagon variant of the Legacy sedan. Additional body cladding provides a more "outdoorsy" SUV appearance. The formula simply works and has done so brilliantly since late 1994 when the Outback was launched as an early 1995 model. Last year, for example, Subaru claims it sold a new Outback every 2.94 minutes in the US. The year prior sales were even better with a new Outback rolling off the lot every 2.78 minutes.

Since 2011, Subaru has sold over 100,000 units annually. The Outback generally appeals to buyers who want something off-road capable, though not for serious off-roading you'd get from a traditional body-on-frame SUV, but also a stylish family vehicle at a reasonable price. It's a formula that's worked brilliantly for nearly 25 years.