how common is it for the headgasket to go in the 2004 Grand am?

common repair. poor design

Yes, unfortunately it's a regular thing with these cars.

Poor gasket design. Use Fel-Pro problem solver gaskets. It is a metal gasket that the dexcool will not eat through

its an issue with all GM late model FWD 3.8L V-6 cars supercharged and non supercharged. and it actually an intake manifold issue as well. so expect to have to replace that as well

Its actually on the 3400, and its the lower intake manifold gasket. There is a lawsuit against GM about it, and you can get some money back if you've had it replaced by a shop. My car has been done twice already and it only has 40k miles on it.

i had tp replace the lower intake manifold gaskets and it cost a fortune do you have any more info on how to get reimbursed