Employing the world’s most powerful series production turbocharged four-pot, the Mercedes-AMG A45 S is by no means lacking in power. However, it seems the folks at RENNtech think it could do with some extra oomph, revealing extensive performance upgrades and visual modifications for Affalterbach’s hyper hatch.

The first stage comprises tweaks to the ECU and diverter valve, which the firm says provides a “quintessential blow-off sound”. Thanks to these upgrades, the 2,0-litre petrol engine now produces a whopping 354 kW and 575 Nm of torque, which is sent to all four corners via the German automaker’s rear-biased 4Matic+ all-wheel-drive system.

According to the Florida-based tuner, additional performance packages will be made available later in the first quarter of 2020. Further equipped with a modified turbocharger and exhaust system, the second stage increases peak power to 410 kW, while in the hottest state of tune, the A45 S will churn out a massive 447 kW. A downpipe, replete with a sports catalytic converter, can be specified at additional cost.

Other optional fitments include a suspension lowering kit and bespoke Vosson alloys, the latter offered in 19- or 20-inch guises. The car seen here rides on 20-inch RENNtech performance wheels.