Standard OnStar assistance, optional remote starting, and midyear introduction of a V8 model are among 2005 Grand Prix highlights. Base and GT models have a 200-hp V6. The GTP has a 260-hp supercharged V6. The new-for-'05 GXP has a 303-hp V8. The V8 has GM's Displacement on Demand system, which deactivates four cylinders under light throttle conditions to save fuel. A 4-speed automatic is Grand Prix's sole transmission. Steering-wheel paddles for manual shifting--Pontiac's TAPshift feature--are standard on GXP. TAPshift is available on GTPs as part of the Sport Package. An antiskid system is also part of the Sport Package and is standard on GXP. All models have 4-wheel disc brakes. ABS and traction control are optional for the base Grand Prix, standard otherwise. Base and GT have 16-inch wheels, the GTP has 17s, the GXP has 18s and uprated brakes. Head-protecting curtain side airbags are available for all but the base; torso side airbags are not offered. The remote starting system operates from the keyfob and is joined as a new option by a navigation system. A CD/MP3 stereo is also newly available, and all models gain rear-seat cupholders as well as standard OnStar. Satellite radio and a head-up instrument display are also optional.