I've had my GT N-Line for just under a year and its been a lot of fun. I recently added my first mod (KN CAI) which I posted on the intake and exhaust forum. Going to be looking for an exhaust soon so, any advice would be great.
Congrats! They are fun cars.
As far as exhausts go, it depends on your price.
Axel backs are much easier than full cat back exhausts to install. The only real good options I have seen for our cars are AFE and an Amazon sold version (don’t remember who makes it). Both I think around ~$400.
The EGT 2018 and up Facebook group is another great recourse for any mods you are looking into.