As Fred mentioned above all the performance Golf's get the Soundakator as standard which is built into the base of the windscreen and uses the windscreen itself to act as a sound inducer to give the "fake" sound inside the cabin.
The GTI and R's by virtue of them being petrol and having tuned exhaust systems already give a throaty growl from the outside when pressing on, but the diesel GTD has a much more muffled sound due to the DPF filter incorporated at the engine manifold end of the system.
To give a fake petrol style growl on the outside of a GTD, the Sport and Sound package can be specced on the GTD, which provides a special exhaust system (without a rear silencer box), and with a sound speaker system built in just forward of the rear axle. This speaker can provide a petrol like sound when in sport mode that can be heard outside the car. Also with the S&S package you get factory painted Red brake calipers as well.
