:welcome:
There have been various head gaskets but if it is still on it's original then it is only slightly revised and not completely redesigned as the latest are.
However cars made in 2004 (assuming it was
made in 2004) tend to be a lot less likely to suffer head gasket failure than previous ones. If you like the car then worries about HGF shouldn't put you off. There is a chance of HGF with almost any make of car.
Factory fitted glass rear windows were only introduced in 2005 but any glass rear window is worth having, especially if it is heated and it probably indicates that the car was at one time owned by someone who cared for it and spent some money looking after it.
Edit: Having looked at your picture, I do wonder if you can see out the rear through the rear view mirror

If not I wonder if it is legal! Someone will probably recognise it...