My wife put her almost new (less than a year old) SLC with only 7.5k miles from new in for a service from same main dealer she bought it from. They reported to us that they found metal particles and one 'large' piece in the oil when it was drained. They kept the car for almost 2 weeks and reported back to us this morning that they have stripped the engine and found nothing to be concerned about . They are now going to road test it for a couple of hundred miles and drain oil again and see if they find anything. If nothing found they will give it back to us !! What should I be thinking or worried about please guys.