I have purchased a 2004 BMW 525i petrol automatic, and I am amazed at the very hard ride. On motorways it is perfectly smooth and has direct steering, but as soon as you get on normal or back roads it follows every rut and camber and you feel as if you are fighting with the car. The car is fitted with 17-inch alloy wheels and Dunlop Sport Runflat tyres, size 225/50/R17 -94W. One thing I notice is that if I shift the auto gearshift when in D from S to M, the drive and stability improves. Any advice would be greatly appreciated.