Last July I purchased a pre-registered Mercedes-Benz A180 CDI. On the whole it's a good car, but I feel it has fault. On full lock, the N/S front wheel skips and knocks and, as a 77-year old ex-motor trader, it feels like a faulty CV joint. I have been back to the dealer four times but every time they either say it is normal for this model car or is the tyres and, as for the CV joint, it never fails. The fault shows up most when reversing over a rough surface on my driveway. I'm sure they think I am old fart who doesn't know what he is talking about.