government emissions controls had been tightened and Holden needed to make significant changes to their engines. This resulted in a loss of performance across the range and the deletion of the 2.84-litre straight-six. In addition, a Kingswood panel van was introduced to the range of commercial vehicle offerings. The HX Sandman introduced a large 'Sandman' logo on the tailgate and stripes down the sides. During the course of the HX series, front bucket seats were adopted as standard equipment for Kingswood-badged vehicles. As with the previous series, a couple of special-build HX Kingswood variants emerged later in production, initially with the Kingswood 50th Anniversary sedan in November 1976 and also a repeat appearance of the Kingswood Deluxe sedan. HZ The 1977 HZ series received minor updates to the exterior, and saw the introduction of what Holden termed "Radial Tuned Suspension" (RTS) on all models. RTS made significant changes to the suspension of the car, greatly improving the handling finesse, while at the same time not compromising ride quality. Modern Motor magazine described the HZ as "a great handler spoiled by the car" in a comparison against the BMW 528i, contrasted as "a great car spoiled by the handling". To illustrate, photos were taken of the Holden cornering hard but smoothly, while the BMW spun out of control. However BMW forced the magazine to admit that it had instructed its test driver to throw the BMW into the corner at much higher speed and in a deliberately unstable attitude. In this series, the lower-end Belmont was deleted and the Kingswood became the base model for sedans and wagons, with a new model the slightly more upmarket Kingswood SL introduced. Commercial vehicles—the ute, panel van and cab chassis—were not affected by the rationalisation, with the practice of "unbadged" commercial vehicles continuing. During the course of the HZ series, equipment levels were upgraded in 1978 effectively to match improvements in the opposition Ford Falcon range, but the life of the Kingswood looked set to end following Holden's release of the VB Commodore range of sedans and wagons in November 1978. After 1980, Kingswood passenger cars were cancelled—replaced by the downsized Commodore. The final HZ Sandman, featured a choice of V8 engines only, along with a four-headlight grille and under bumper front spoiler. According to a GMH Price List dated 25 January 1979, a basic HZ Holden panel van was priced at A$6,076, with