Hello, my c200k 51 plate just started to make a sound like a stone in the tyre. according to my wife it only sounds when she drives ,not stationary, but she says it seems like its inside. ? It speeds up accordingly, then maybe coincidently about 10 miles after the noise started the brakepad worn lining malfunction message came on the computer. I also had some new wheels and bolts fitted about 2k ago. Any ideas, I need to get it fixed with least expense as I am in the middle of selling it. Many thanks Paul