All modern cars have a obd2 connection which is used to for example read fault codes or reprogram software.
There are some cool apps available that you can use to for example modify your car. Volkswagen and Audi cars can be pretty easily modified even remapped if you have the right performance maps for your car.
Other popular apps are torque pro which let's you reset fault codes and maintenance notifications. You can also use your phone or tablet as an external display to show important engine and car information like turbo pressure for example.
One of my favorite apps is revheadz, this plays some artificial engine sound through your car speakers which matches your real engine rpm.
You will need an Obd2 adapter with bluetooth. You can buy an adapter for cheap on amazon or ebay and also use it for other handy things. (Like read fault codes of your car or change hidden settings)
Revheads app (This is the app i used, they have a free version but not all engine sounds are unlocked. For some things you have to pay but the basic version is free.)