I just got an e mail from my wife after she picked up my 04 Chevy D/A. It was at the dealer for an oil change, rear end fluid changed and a tire rotation. On the invoice it said "Job #2: lube, oil, filter, change smart card LOF" Any one have any idea what change smart card is? Also is $175 for the rear end fluid around normal? For all this work plus a tire rotation ran me $271. And they didn't even reset the oil life monitor. I would find this out myself from the service department but I am overseas so all is on my wife to handle. Thanks.