I park my 2011 1.7D Premium ix35 reversed onto my sloping drive, SOMETIMES (no pattern) when I start there is a terrible rattling noise for about 15 to 20 seconds. I check fluid levels regulalrly and have never needed to add oil between services.

The car has been back to dealer and they have found nothing, as it has happened 4 times in last 3 weeks, I am taking it back to dealer on Monday.

Any suggestions what it could be, so that I can pass onto dealer???