The straight-piped supermini sounds absolutely insane.

Audi has been going back and forth about engineering a hotter A1 based on the supermini’s latest generation to follow the old S1 hot hatch. The tuners at ABT decided to take matters into their own hands and prepared an amped-up version of the stylish city car about a month ago with a bump in output from the series 197 bhp and 236 pound-feet to 236 bhp and 266 lb-ft.

The tuned A1 Sportback pales in comparison to ABT’s latest one-off creation as this wild subcompact hatch is on the same level of insanity with the ultra-exclusive A1 Quattro limited edition from many moons ago. Side note, the pocket rocket was actually tuned by ABT back in the day and was taken from the stock 256 bhp and 258 lb-ft to 307 bhp and 295 lb-ft.

Gallery: Audi A1 Sportback one of one by ABT Sportsline

This “One of One” A1 packs an even mightier punch as ABT has installed the motorsport-spec 2.0 TFSI engine from the TT Cup race car. Its four-cylinder turbocharged mill produces 310 bhp, but there’s an overboost function temporarily squeezing an extra 30 bhp for a grand total of 340 bhp while torque is over 295 lb-ft at all times. The German tuner has already fiddled with the engine to take it to around 400 bhp, while the brutal soundtrack provided by the four-banger is enhanced by a straight-pipe exhaust system that your neighbours would probably hate.

Sitting close to the road on 19-inch forged aero wheels, the A1 Sportback is 55 millimetres wider at the back compared to the donor car thanks to the bulging fender wings. The rear doors of the little Audi have been covered, while the back has gained a massive wing and a look-at-me diffuser flanked by the two fat exhaust tips. There’s more to the body kit than the wider hips and new attachments as some of the other panels have been replaced, including the bonnet and even the door mirror caps.

Regarding the two-tone livery, it’s similar to the black and white RS6+ Avant Phoenix built by ABT for Jon Olsson last year. As a matter of fact, this black and red split theme was actually created by the same talented man. The interior also went through some changes as the rear seats were taken out to make room for a roll cage while the front ones are bespoke body-hugging seats as you’d expect from a proper hot hatch. Loads of Alcantara finishes along with a flat-bottomed steering wheel round off the cabin changes.

There’s still some work that needs to be done, namely suspension tuning and making the final engine adjustments, but everything else has been finalised. Since this is a one-off project, the car is not for sale. Given the amount of work and time invested in the build, it would probably cost an arm and a leg.