I have a problem with the ride quality on my BMW 530d 2002 . The car has air suspension. mileage is 177000 miles. I do not have the service history. When I bought the car the ride was super smooth but now it is a harsh ride. The car goes THUD THUD THUD on bumps in the ride. I have had the car checked over by 2 garages. Tyres, air compressor, shock absorbers etc all okay. I asked the garages to check the rear suspension subframe bushes but I was told they are okay. I understand the bushes are fluid filled and it may be difficult to tell from a visual inspection if they need replacing. Any advice?
