For quite a while now, BMW has been offering the so-called M Performance Parts for a variety of models and engines. One of the most popular ones, whilst we're waiting for the new M3, is the M Performance Power Kit for the 335i, that we covered earlier.
It will bring 20 extra HP and 43 Nm (32 lb-ft) of torque to the total of your car, reaching 320 HP and 450 Nm (332 lb-ft) of torque, plenty to make the 335i with an automatic gearbox just as fast as an E90 M3.
That is impressive. For just $1,100 (€857), your car will feel completely different and will be done by BMW in their dealerships so that you can continue using the warranty. That's actually the main problem with aftermarket products.
Just as Grand-Am champion, Scott Pruett says in the video below, you might find better alternatives but all of them will forfeit the warranty for your vehicle and that is not something to be taken lightly.
For those of you that prefer visual tuning too, BMW is also offering the M Performance Parts as an aerodynamic kit that looks absolutely amazing. More details here.
Google News