Over the past few weeks, I have noticed a randon metallic tinging or pinging sound coming from, I think, under the car behind the engine, middle of the car. When you pull away you can hear this 'ting, ting' or single knock. Notice it more when driving past buildings/stationary cars with the window down. Pop the car into drive pull away, then almost immedialtely you can hear 'ting, ting', 'ting', 'ting, ting', just random. Nothing appears to be loose, no fluids leaking anywhere, all appears normal, so I am thinking it's something internal to g/b or engine. However, sometimes it doesn't happen at all, but 995 of journeys, you can hear it! The car is a 2.0Tdi 1.7 DSG/Sportronic, 2007 MY, with 58K on the clock. The gearboax oil was changed in October 2011, following a full service. Car has been pefect up until now. Took it in to Audi-VW dealer to check. Their diagnosis is that it could be either DSG box or Dual Mass Flywheel but not really sure without extensive work. Gulp! Can anyone shed any light on the symptoms I describe and help/advise???