people driving in audi's are the ones who annoy me the most, because they always think they have something to prove. i would say 80% of the time i get challenged on the highway, its from an audi driver.
i also hate hyundai drivers, but thats because they just flat out cant drive and are always blocking me, driving up my rear end, or keep passing me then slowing down so i have to pass them for the 13th time.