When it was launched, the GT R had several cosmetic changes compared with the standard car, notably the vertical slats in the front grille, an adjustable rear wing, new front air intakes and new front and rear diffusers. The styling of the GT R is more comparable to that of the AMG GT3 race car. However, the base GT variant gained several of these cosmetic changes as part of a mild facelift in the 2017 model year. The GT R went on sale in November 2016, with deliveries beginning in 2017. For the 2018 Formula One World Championship, the GT R became the official Formula 1 safety car. It completed a lap of the Nürburgring Nordschleife track in 7:10.92, in a test conducted by German magazine "Sport Auto." This earned it the seventh position for street legal vehicles in 2019. A roadster version was introduced in March 2019 and would be limited to 750 units. The GT and GT C roadsters are the roadster versions of the GT and GT C coupés, and were announced shortly after the introduction of the GT R variant. Both variants made their debut at the 2016 Paris Motor Show. The GT and GT C roadsters utilise the active air management system found on the GT R variant to help with cooling and airflow performance. The GT C roadster retains the wider bodywork of the GT C coupé, and the GT roadster has a slightly higher first and lower seventh gear with a longer final drive compared to the GT coupé. The GT and GT C roadsters feature a three-layer fabric roof built around an aluminum, magnesium and steel structure, available in black, red or beige, and which can open and close in 11 seconds up to speeds of . The GT C roadster, like the GT C coupé, has a limited "Edition 50" model, celebrating AMG's 50 years of existence. A 5-door liftback version of the AMG GT was introduced at the 2018 Geneva Motor Show. In 2020, spy shots of car spotters on or near the Nurburgring Nordschliefe have revealed that there are camouflaged prototypes of the upcoming Mercedes-AMG GT Black Series. The spy shots have revealed a newer and more aggressive front end, a taller rear wing, and different wheel rims for the front and rear tyres. Mercedes-AMG have yet to unveil the car to the world. In March 2015, Mercedes-AMG presented the AMG GT3, a race version of the GT, at the Geneva Motor Show, which employs the "M159" V8 naturally aspirated engine also used in the SLS AMG GT3.