WRC 7: Porsche Car

If you purchase the main game on Steam, this DLC is already included (free of charge) until 29th of September, 2017 as part of the Day One Edition.

Make a dream come true by getting behind the wheel of a legendary model: the powerful Porsche 911 GT3 RS R-GT driven by Romain Dumas, a driver in the FIA R-GT Cup.
Driving a rear-wheel drive race car is an unparalleled experience in WRC and presents a unique challenge for any players looking for new experiences.
The Porsche 911 GT3 RS R-GT is accessible in all game modes (except Career and personalized Championship) and for all the rallies, in the “Bonus Cars” category.

Source: Steam Store Description