DSG Gearbox/Clutch Specialists in NorthWest

Hi all,

We have a 2006 Skoda Octavia (mk2) which has the DSG gearbox. For the past few months we've had a noise come from the gearbox area in the engine bay, it's like screws rattling around a can (quite noisy and irritating, as you can hear it from inside the car). it only happens when the car is in Neutral or in Park. If you put it in Drive and hold the car on the brakes, the noise goes away.

After doing some research, I think it might be the Dual Mass Flywheel but I need someone experienced to confirm it and give me a reasonable cost to get a new one fitted, before a catastrophic failure occurs leading to several $$$

Does anyone know of a decent independent transmission specialist in the North-West that could help diagnose the problem and give a reasonable cost for the work needed? I don't want to go to some garage who doesn't really have a clue but will take the job on and in turn lead to major hassles...

Thanks for your help!