Took the Buick to the Buick dealer today for an oil change and tire rotation. Upon inspection they advised me that my rear head gasket is showing signs of leakage. Not serious at this point but problem will have to be addressed soon. Estimate of $1800. to repair. Needless to say my extended warranty ran out 6 weeks ago! My husband and I are having difficulty believing that a head gasket needs to be replaced at 82,000 miles. We've had vehicles with over 150,000 miles and never had a head gasket problem. Is this something GM knows about. If this is the case it should be a recall. I don't believe for a minute that we should have to pay for this repair for a vehicle that has always been dealer maintained, never abused, and is in like new condition inside and out. Anyone else having this problem.