I am sorry that everyone has had bad experiences with Pontiac Sunfires, but I have owned two and not had any major problems! I had a 1999 model, that I traded in at 68,000 miles for a 2002 model.
The problems I am having right now are because my car has 110,000 miles on it, not because it's a GM/Pontiac. Plus my car is not garaged, which does make a difference, too.
One of the muffler straps broke at 110,000 miles, and I have an small Anti-Freeze leak, which is leaking into the one vent of the AC/Heat.
I believe that once a car is over 50,000 miles beware... anything can go wrong. That's why most car companies only offer 3 years/50,000 miles as the standard warranty.
I don't believe in buying a used car w/o a warranty, or keeping a car after the warranty, if you can help it... cars don't last forever, like in the good old days.