Audi wants a lot of money for the privilege of owning the RS3 or the TT RS. And many people are willing to pay because the 2.5-liter engine is just so special. But with a good tuning kit, even the 2.0 TSI can reach 400 horsepower.

Let's stop for a second and think what that means because the A45 has numbed us to the implications of these kinds of numbers. We're dealing with 100 horsepower per cylinder or 200 horsepower per liter. They are racing motorcycle levels of output.

This is by no means the most powerful version of the 2.0 TFSI out there. But the fact that ABT based their project on the S3 Cabriolet deserves extra attention. You see, this body style is going to be discontinued, plus you can't buy an RS3 Cabriolet, only a hatch, and sedan.

So if you want a 400 horsepower Audi convertible, it's either this or the S5. Anyway, we have to look at what they're offering, starting with the power boost. This was achieved through a custom control unit for the turbo engine that's designed to work with a port catalyst in the exhaust and better induction management. If you just want the software, that can still get you 370 horsepower and 480 Nm of torque, which is more than the outgoing RS3 Sportback. But the new 0 to 100 km/h time of 4.6 seconds reveals the limitations of this platform.

To compensate for the A3 Cabriolet's softer body, ABT also installed sport anti-roll bars front and rear. They went easy in the cosmetics department, only adding some 2-inch two-tone wheels and fender vent inserts.

"For the perfect look, all that's missing now is the special door entry lighting, which projects the ABT logo on the floor when getting into the car. And that's the one, and only reason why a proud owner of this attractive convertible would ever put his head down," the one-stop-shop for Audi tuning says in its press release.

RS3 levels of power in a convertible is kind of cool. But ABT has spoiled us with much better project at the Geneva Motor Show. Check out their RS6 and the body kit for the R8, which is our current favorite look for the German supercar.

Read more on Autoevolution.