My wife recently bought a 2004 Nissan Sentra 1.8L from Carmax. I checked everything out before it was paid for and nothing looked neglected or damaged. We both read up on many reviews of the car and there was absolutely nothing bad about this particular model except for the looks. I skimmed through all of the UOA's on here and unfortunately it looks like Nissan had some problems with the head gaskets for this engine. There was only one 2004 UOA and it did not have a head gasket leak. I noticed a lot of the previous year models had them. Anyone else seen a head gasket issue with the 2004 models? I am going to send off an analysis to Blackstone when I change the oil in it just to make sure she didn't purchase a car that had a leak. Carmax gives 30 day warranty, can be extended up, plus she gets the remainder of the original 3 year/36,000 mile warranty from Nissan. Which would be about 1 year/8,500 miles as the vehicle has about 26,500 miles on it.