Any of the major American oils in SAE 10w30 weight will be fine.
5W-30 according to the manuf.
5w30 synthetic blend motor oil 4.7 qts.
134A
Dexcool
4 wheel disk
eaton m90
r134 a r134 a
R-134a
Have you checked your coolant? Kind of obvious but sometimes overlooked.
Yes, 2004 Grand Prix is a very good car. But a good car really depends on how well the previous owner maintained it, not what kind of car it is.
DOT 3
There will be an input of some kind