BMW keep beating around the bush with the F30 version of the M3. The sedan is out for some time now, the tests are done and people are interested.
While they’re having fun with a lot of M Performance products, special diesels and revised all wheel drive products, tuners are showing what can still be done with the old one.

A nice example here is ATT-TEC Tuning, a company which decide to breathe some extra life into the E93 BMW M3 Convertible.
A dark foil wrap, a lowered suspension and new 20 inch forged alloy wheels wrapped in Vredestein Ultrac Sessanta tires make for a very aggressive look.
The two tone black, the decals and the point spokes on the wheels make the M3 look very badass, but is it? Well, the standard car isn’t really.

That’s why the guys at ATT-TEC went over to G-Power and bought a supercharger kit. That’s how the 4.0 liter V8 now gets some considerable boost.
Final output for the E93 M3 convertible stands at 520 horsepower which is 100 more than the standard one.
Just to make sure people know the sort of grunt that lies under your bonnet, a sports exhaust kit is also there to make some noise.

You’re likely to enjoy the sound yourself as well but that’s another story. As is the price you’ll have to pay to get one of these ATT-TEC conversions.
The entire kit comes in at roughly 35.000 USD which is the cost of quite the capable second car. You can even get some specially prepped trackday motors for that money.