Apparently, that model year had noted issues with motors that consumed excessive amounts of oil, some reviewers complained about squeaks and rattles in the interior, and most people note that the brakes wear out quickly.
RE: oil - requires full engine replacement, or just continually supplying the car with oil. BTDT on the constant supply, unless it requires expensive oil, not a major killer.
RE: squeaks/rattles - bothersome, but puzzling. The I30t doesn't have any squeaks, my Grand Prix sounds like it's shaking apart. I expect the G to be much closer to the I in that respect.
RE: brakes - soft pads for better braking. Since I can change them at home, again, not a major worry. Sounds like a once a year replacement, and maybe $200 tops?