NMB123

Hi all, I have just purchased a nearly new A3 Sportback with 2,600 on the clock from an Audi dealer. I am surprised by the amount of road noise that I have encountered on a recent 200 mile round trip to the Midlands from London. The car is running on Bridgestone Turanza tyres (18 inch) and the actual tyre noise itself does not seem excessive. However, the vibrations from the road are creating a reverberating droning noise which is present at all speeds but worse at over 60 mph and gets worse the rougher the road surface. The noise is present even when the car is in neutral and is coasting, so I do not think it can be the engine or transmission. It is really irritating and is spoiling the enjoyment of what, otherwise, is a very nice car. Has anyone else experienced this and is there a cure? Thanks