The Abt squad has emerged as the quickest team within the Audi stable this year, with its drivers Nico Miller and Robin Frijns winning half of the races between them in the opening four rounds of the season.
Muller started his campaign with a run of three victories and has finished on the podium in all but one race since then, while Frijns scored his maiden win at Assen after a string of top results.
Abt’s dominance has left Team Rosberg driver Rast a distant third in the drivers’ standings, 44 points down on championship leader Muller, after the two-time champion could finish no higher than fifth in either race at Assen.
Asked how frustrated he was with his results in the wake of Abt being so far ahead of its fellow Audi teams, Rast told Motorsport.com: “Very frustrating as you can imagine. In qualifying when I do a good lap this year it’s not enough for pole-position anymore. Last year when I did a good lap, it was mostly good enough for pole-position.
“And if I did a mistake [last year in qualifying] it was probably still good enough for P2. But [on Saturday] I did a good lap [and qualified sixth]… it’s just really difficult.
“We don’t have the pace to fight the Abt cars at the moment. As you could see in the race and qualifying both Abt cars are amazingly strong. And Nico and…