Used parts availablity for discontinued cars.

[dieseljeep]

One of my neighbors has a real nice condition Saturn four door car.
The rear driver's side door is totally trashed, but the car seems undamaged otherwise.
Is the used parts that hard to source? GM only made those cars for a few years.
A friend said GM threw Oldsmobile overboard to start a new car line.
What say, old car experts.