Ok, I'm back : ). I don't think HSV is in GT4 because they are in other dodgy games for the moment. Anyways after the XU1 Toranas and the XY GTHO phase 3 were released a jouranlist called hmm I can't remember at the moment, well he wrote an article about how the new Australian "Super cars" were too dangerous and it was costing alot if peoples lives because they were undrivable in bad conditions. There was some truth to his story because back in the day and Falcon GTHO could smoke the tires through every gear in the gearbox no problem, but you have to remember road tires in 1970 were not anything like the sticky tires we have today. This is also why the origianl quarter mile times of the GTHO and the XU1 and also the E49 Australian Charger are all in the mid 14 seconds when in fact all those cars can cut a 13 second quarter mile on modern tires. Anyway the factories were under pressure and so the Holden V8 powered XU2 Torana and the new Phase 4 GT were cancelled. You have to remember that the LJ torana weighed only 1000 kg's and had over 200 hp, the Charger had 300hp and was the fastest 6 cylinder in the world at the time and the GTHO was the fastest 4 door car in the world.
Ok so after all that drama Holden brought out the larger new LH Torana which although it had a weak gaerbox and diff still managed to win bathurst. Ford made some revenge after that and had a famous victory at the Bathurst race with a 1st and second place in it's 2 door Falcon coupe (same car as mad max's interceptor). But then is was all over for Ford for many years because Holden introduced the infamous A9X Hatchback Torana, It had a stronger gearbox, strong diff and a strenghtend 308 Holden V8 developed by Repco (who were into open wheel racing at the time) and it owned bathurst, Peter Brock cruised the whole race and then set a lap record on the final lap just for fun, getting the thing up on two wheels through the "dipper". That was the end of the line for the Torana hatchback. It was replaced by the first Commdore. which was a strenghtend "Australianised" version of Opels car. Much in the same way as The Torana began it then evolved more and more. In 1987 or so, Tom Walkinshaw of Formula one fame developed the Walkinshaw commodore which was the first fuel injected version of the Holden V8, it ran twin throttle bodies and a huge racing body kit of the likes that had never been seen on the road before and only came in one colour, Mount Panorama (the bathurst track) Silver (but it's kinda green). Then came the new shape Commodore also an "Australianised" Opel. This VN Commdores star model was the VN Group A SS, a 6 speed manual fuel injected (once again with dual thorttle bodies) Holden V8 with a top speed of 250km/h. It ran 0-100 in 6.5 seconds and a quarter mile in 14.7.
Now we were once again aproaching the speeds of the cars that caused the orginal super car scare. The Holden V8 had not changed much over the years. The biggest changed were the L34 kit that came with the LH torana, it just had strenghtend the block and rods and better heads. Then it was down sized to 304 inches in the early Commdore so it could pass into the 5 liter and under class in international touring car racing. The final version of the Holden V8 was intorduced in the VN Commdore, it continued thorugh the VP, VR, VS and half way through the VT model. Then production was shut down and Holden imported the new LS1 Chev V8. By now we in the late 90's entering the modern Holden times since the VT Commodore we have had the VX, VY and the new VZ. With the VZ was introduced the latest Chev V8 and Holdens new 6 cylinder "Alloytech" motor that is the new 6 cylinder motor for all general motors cars, including Saab. Holden have also not long ago played with the idea of re introducing the Torana with a turbo charged version of this motor, they even built one ugly concept car along these lines (twin turbo) (the have also played with a concept of a new Torana hatchback a couple of years ago). The current Monaro also started as a concept car and the public demanded Holden to build it. That's how that came about. Then the boss of Pontiac demanded he sell Monaros as the new GTO, GM also loves the Commodore ute and I guess you will see a new El Camino over in the states one of these days : ). The ute racing you see on cable, well they are all stock V8 utes the same as farmers and tradesmen in Australia use for work cars.
I guess another car worth mentioning is the VL Commodre 6 cylinder because by the early 80's the RED motor had become the BLUE motor in the VC Commodore (same but stronger rods from a crapy engine called the "starfire" which was a RED 6 with two cylinders choped off and stronger rods

, the new BLUE motor also had a 12 port head instead of 9 ports). It then became the BLACK motor in the VK Commdore which was just a fuel injected version of the BLUE one. But for in 1986 Australia finally swaped to unleaded fuel and Holden decided to retire the old beast and get a new engine.
So for the VL Commdore (last of the original shape) They used the same Nissan straight 6 that the Skylines run except in 3 liter size. It also came with a Turbo option and that is still one of the hot street cars of today.
Well you can google information about any of those cars I've talked about or I can go and take some pictures of some. The older cars are pretty rare now so it's hard to get picture of them but most of the Commdores are still around. (I actually saw one of the 500 Walkinshaw Commdores that were built down the street two days ago)