i've owned my 2004 gtp compG for a year now and it's a great sleeper. i love the way that my plane jane white pontiac just looks like any other commuter, but inside the engine bay is a killer motor. mods i've done so far........the other guys headers, header wrap,high flow CAT, k&N CAI, billet motor mounts and supports, chip reflash, Garvin NAV, and mP3 upgrade on stereo.
i also got a set of Goodyear F1 GS tires, a great tire for the rainy west coast. top speed 237Km/h (that's what the HUD said anyway). still get around 8.5L/100Km in regular driving too!