I think the Cobalt SS Brembos are the only ones that fit and require a rotor change. I kept mine stock but switched to D/S rotors with some nice pads and braking seems to be a lot better.
Sent from AutoGuide.com App
2009 Techno Gray Metallic G6 GXP Sedan (3.6L Auto6 112K miles)
CRAB Intake Opt 3 w/FPU, Lloyds GXP floor mats, HIDs low 6000k 55w/fog 3000k 35w, LED DRLs behind lower grills, V3 Triton LED turn signal/reverse/brake, LED side markers/maps/dome/tag/trunk/high mount stop, 2 coats niteshades on tails, Tint 35% all around, Debadged (except arrows), PAC IPod and BT adapters, PowerStop D/S rotors and ceramic pads, Resonator repl w/24" cherry bomb, Racingline STB, Big 3 Upgrade, Optima Yellowtop D75/25, Blacked out arrows, chrome window trim and black dipped wheels, KYB struts and shocks, CM lowering springs, Cherry Bomb Vortex Crossflow muffler, 2.5" pipe from axle back, two 4" stainless double walled slant tips