My 2012 C63 started smoking from rear of engine after giving it some welly. Rang Autoprotect warranty and they said to get it diagnosed at my cost then get the garage to ring the for authorisation. I purchased a new seal set as the cover would be coming off to diagnose the problem. Turned out the camshaft cover had a crack at the rear of cover near bolt hole. Garage rang Autoprotect for authorisation - sorry not covered as it’s not a mechanical part. Why didn’t they tell me that during first phone call, I could have saved £200 and done it myself. Paid for new cover and 7 hours wait and job was complete - £450 crack Has anyone else experienced this?