The new Mercedes-AMG A45 S has been tuned by Posaidon, with its four-pot boosted to 386 kW (and its top speed hiked to 324 km/h).

Using the firm's twin-scroll turbocharged 2,0-litre four-cylinder engine as a base, the German superhatch has had its peak outputs increased from the standard 310 kW and 500 N.m of torque to 386 kW and 600 N.m. The German tuner achieved this by adding an upgraded turbocharger and optimising the engine mapping. Along with this, revisions have been made to the control unit for the AMG Speedshift dual-clutch transmission.

With the RS 525 package fitted, the A45 S manages a claimed 0-100 km/h time of just 3,4 seconds (half a second quicker than standard) and a top speed of 324 km/h (up from 270 km/h). Posaidon points out these performance figures are similar to those of the Ferrari F40. Those looking for a little less drama can spec a lower-tier upgrade which sports a 342 kW and 560 N.m power output with a 0-100 km/h time of 3,6 seconds and a top speed of 318 km/h.

Posaidon also offers 20-inch carbon-fibre Evolution One rims weighing 4,9 kg each. The company says it will soon also sell you a high-performance braking system and a cat-back sports exhaust system. These upgrades can be fitted to other Mercedes products that use this powertrain, such as the CLA45 S and GLA45 S.

Furthermore, the firm confirms it is currently developing a "Plus" package with even more power...