I have Carmax's extended warranty too. Glad they didn't try to nickel and dime you. In my most recent repair (oil pressure sender unit) the dealer hit me with an extra $50 in labor over the deductible. Carmax would not cover the time to remove and replace the 4XGuard skid plates because they were aftermarket accessories. Dumb. First time I had that issue. Next time I will pull them before it goes in. Ten minutes of my time tops.