The Audi RS lineup has been expanding thanks to new entries such as the RS Q3 Sportback and RS Q8, but have you ever wondered what goes into making the sportiest vehicles from the four-ringed brand?

If so, you’re in luck as the company has pulled back the curtain and revealed some details about how RS models are born.

Given their positioning as the sportiest of all Audis, RS models have a unique design that is “very much inspired by motorsports.” Of course, vehicles are also designed with performance in mind and cooling plays an important consideration.

Also Read: Audi RS Q8 Breaks Nurburgring Lap Record For SUVs

Besides featuring large air intakes, RS models are distinguished by oval tailpipes which “symbolize the power” of their turbocharged engines. The models also have unique grilles which largely eschew chrome trim for black accents. In the case of the RS 6 Avant, only the front doors, roof and the tailgate carryover from the mainstream A6 Avant.

As countless spy photos have proved, Audi extensively tests their RS models on the Nürburgring Nordschleife. As they explained, the Green Hell is one of the challenging tracks in the world as more than 80% of the 12.9 mile (20.8 km) long course is driven at full power.

Audi went on to say with “maximum load applied in fast motion, every kilometer on this course equates to multiple kilometers of regular road operation.” That’s part of the reason why every RS model has to complete 4,971 miles (8,000 km) of endurance testing on the Nordschleife. As the automaker explained, if you can survive there, you can survive pretty much anywhere.

Of course, RS models are also tested elsewhere and Audi noted the RS Q8 spent two years racking up more than 745,645 miles (1.2 million km). That’s the equivalent of driving around the world 30 times.

The high-performance crossover was tested in a number of different countries including China, Italy, France, Finland, Sweden, South Africa and the United States. These different locations allowed engineers to do cold weather testing in Scandinavia, hot weather testing in South Africa and high-speed testing at the Nardò Ring in Italy.

Audi currently has 12 RS models, but noted they have “many more ideas for the near future.” While the automaker wouldn’t elaborate, spy photographers have already snapped the redesigned RS3 on multiple occasions.

Audi went on to say “Future RS models will enhance the range relatively soon after the launch of the respective base product lines.” They noted these upcoming models were developed alongside their mainstream counterparts and the RS team is focused on adding “sporty DNA” through design, powertrain and suspension changes.