I bought a new GLC AMG line (01 March 2016, 16 plate) which has 20" rims and Bridgestone RFT Dueler H/P Sport 255/45R20 run flat tyres fitted as supplied by Mercedes Benz. They are very noisy whilst manovering at slow speed and as one of the other disgruntled customers above suggests, I too often find myself apologising for the excessive noise, grabbing, clunking from the front of my car whilst parking etc. I took the car back to the dealer on the 22nd March and the service manager explained that the problem was likely due to cold tyres and was not an issue, once the cars tyres warmed up, he explained, the problem would go away (amazingly he did add that in time, following feed back, MB may decide that the tyres and wheels fitted to my GLC could be found to be unsuitable!)
I began to live with the problem as the weather improved into the spring and summer months. A couple of weeks ago I went to Manchester in the car where the weather was very cold, much colder than here on the south coast. The car performed terribly so much so that my 92 year old mother refused to get in the car after experiencing the dreadful noise. My wife will not drive the car as she thinks the wheels are falling off. The dealership have very little interest only to say now that they "haven't heard of this problem before, why don't I bring the car in for them to look at etc..." I thought it was down to the run flats but it sound like Tony above believes run flats will solve the problem so he must have another tyre fitted to his 20" rims which clearly show signs of performing much like the run flats. (Don't waste your money Tony, the problem will not be resolved by fitting run flat tyres)
The noise, lurching, grabbing, clucking etc from my Ł43,000 car is so embarrassing especially when you have people in the car and they start to feel unsafe. Mercedes need to sort this out. I like the look of the car so much but my confidence in MB has been knocked and I doubt that at this time I could consider buying the brand again.