My GLA 250 4-matic suddenly overheated- warning light came on saying "engine coolant temperature dangerously high". Car was towed to dealer. After 5 days I was told the water pump was the culprit and needed to be replaced. The car has 6500 miles on it. They replaced the water pump but told me the malfunctioning one visually looked fine. Nothing broken, no worn bearings, no obvious leak. I heard nothing in the engine prior to the overheating and did not notice any leakage of fluid in the driveway. Obviously I am not happy about this- engine failure at 6500 miles with no good explanation does not bide well. Apparently they have seen this issue in 3 CLAs- one at 30k, one at 15k, and one at 5 k miles. The dealer never got feedback from Mercedes as to what the issue was with the failed water pumps. How do I know this won't happen again? I don't feel comfortable driving this car far from home as I still don't know what the problem was. Anyone heard of this issue in GLAs?