If you don’t mind your BMW X5 or X6 having active sound generation to trick you into thinking you have a loud, sporty V8 engine, then this app by Hamann could interest you.

It is available exclusively for the M50d engine configuration on the two aforementioned models. Hamann installs the app functionality into the car along with a custom set of stainless steel sports exhausts.
hamann apps
The app controls not only the synthesized sound you hear from the speakers but also flaps in the rear resonators. You can pinpoint the resonators in the photos below as being the spherical shapes from right behind the mufflers.

Obviously, you can tailor the new sound using a smartphone, where you can adjust the pitch, volume or other parameters that affect the final noise you hear. You can even “virtually accelerate” using this app, in order to gauge what the sound you’ve chosen will be like on the move. By: carscoops