ball type with a power assist option. The brake system features front disc brakes with solid rotors, and rear drum brakes. Power assist was optional starting in the 1975 model year. Models and changes The Astre features Pontiac's trademark split grill, emblems and steering wheel with an upgraded interior trim to help differentiate itself from the Chevrolet Vega. Other styling differences compared to the Vega include — 1973 model Astres have a black-finish grill and clear parking lamp lenses on all models, and chrome headlight bezels on non-GTs. Taillight lenses (same as the Vega) have a chrome trim piece surround. The 1974–1977 models have first generation Firebird-styled taillights (also shared with the 1973–1974 Ventura) on the notchback and hatchback. The hatchback coupe features a lower roofline and a fold-down rear seat. The notchback sedan had the lowest price and is the only Vega model with an enclosed trunk. The Safari wagon has fixed rear-side glass and a swing-up liftgate. A panel delivery based on the wagon was sold through the 1975 model year. It has steel panels in place of the rear-side glass, and an additional enclosed storage area. An auxiliary front passenger seat was optional. The SJ hatchback and SJ Safari wagon models feature soft nylon upholstery, cut pile carpeting, padded and cloth covered door panels, and a fabric headliner, plus rally instruments, the higher-output two barrel engine, four-speed or automatic (over a three-speed manual) gearbox and radial tires. A GT package option for the hatchback and Safari wagon combined the lower-line interior with the SJ's performance and handling features. The 1974 model year brought the only major body design changes, due to revised front and rear bumper standards-A slanted header panel with a new split grill and recessed headlamp bezels complement the larger, front 5 mph aluminum bumper. Front and rear license plate brackets were relocated and a larger rear 5 mph aluminum bumper was used increasing the overall length three inches compared to the 1973 models. A revised rear panel on notchback and hatchback models had new Firebird-styled taillights and ventilation extractor grills were eliminated on trunk and hatch lids. The 1975 Astre, introduced in the United States September 1974, gave U.S. Pontiac dealers a needed fuel efficient subcompact. A budget "S" series was added during 1975. More than 267 changes were made including new High-energy electronic ignition system and a catalytic converter. Power brakes and a