Words: Kyle Cassidy
Published 17 December 2025
Audi has unveiled a striking one-off concept to celebrate 50 years of its five-cylinder engines, with the retro-styled GT50 paying homage to some of the brand’s most memorable race cars.
The GT50 concept was created to mark half a century since Audi first introduced a five-cylinder engine in the Audi 100 in 1976. That original 2.1-litre unit produced 100kW, laying the foundations for a layout that would later define Audi performance through models such as the original Quattro, dominant rally cars of the 1980s, the RS2 Avant and today’s RS3.
Details of the GT50 have emerged via German publication Stimme and its associated social media channels. The concept was developed over six months by a team of 14 apprentices at Audi’s Neckarsulm facility, making it the fifth apprentice-built concept produced at the site.
Using an RS3 as a starting point, the team undertook a dramatic transformation. The donor car was stripped of its doors, roof, bonnet, boot and interior, before being reimagined with an entirely new body constructed from fibreglass-reinforced plastic. The roof itself was sourced from an Audi 80 sedan, further reinforcing the project’s retro roots.
Visually, the GT50 draws clear inspiration from Audi’s American touring car legends, most notably the Audi 90 IMSA GTO and Audi 200 quattro Trans-Am racers that competed in the US during the 1980s and 1990s. Compared with the modern RS3, the concept adopts flatter surfaces, pared-back detailing and blunt front and rear ends, echoing the boxy aggression of those race cars.
That simplicity also throws the more extreme elements into sharp relief, including an oversized front splitter, prominent boot-lid spoiler, rear diffuser and heavily flared wheelarches. The alloy wheels reference designs used on Audi’s Le Mans endurance racers, while track-focused touches include side-exit exhausts and a bespoke roll cage.
The GT50 continues a tradition of ambitious apprentice projects at Neckarsulm. Previous efforts include the NSU EP4 concept revealed in 2023 and the RS6 GTO concept from 2020, which later inspired the limited-run RS6 Avant GT launched in 2024.
