Om Pukekohe Park Raceway:
Although Pukekohe Park Raceway is better known internationally as a motor racing circuit, it is primarily a horse racing circuit in New Zealand. It is located 40 kilometres (24.9 mi) south of Auckland City in the North Island. The track is now owned by Pukekohe Park Limited. In the centre of the circuit there is a horse racing course, which dictates the use of the site as it owned by the Counties Racing Club.
The Raceway was opened in 1963 as a permanent track, replacing Ardmore (an aerodrome) as the host circuit of the New Zealand Grand Prix. Annually for several years, the mainly European based Grand Prix drivers such as Stirling Moss, Graham Hill, Jim Clark and Jackie Stewart, would head downunder for a relaxed Tasman Series during the European winter.
For many years Pukekohe was the venue for New Zealand's premier production car race, the Benson and Hedges 500 mile race (later 1000 km) featuring drivers such as Peter Brock, Dick Johnson and Jim Richards. In 1996 the New Zealand Mobil Sprints held one round in Pukekohe. Pukekohe Park Raceway also held an annual round of the popular Australian V8 Supercar race from 2001 to 2007. However, the New Zealand round moved to Hamilton Street Circuit in 2008. On the 5th July 2012, it was announced that V8 Supercars would return to the circuit in 2013 as part of a 5 year deal with the circuit operators.
In the centre of the circuit there is a horse racing course, which dictates the use of the site as it owned by the Counties Racing Club Inc, who had not invested a large amount of money in the motor racing track over the years and many would say that this would leads to its slow demise. Even though the club holds very few horse race meetings each year, it is used as a stables and training facility.
However, on Oct 15, 2012, New Zealand Herald reported that the raceway is to undergo a NZ$6.6 million upgrade which will allow the V8 Supercar Championship to return there in April, 2013. Auckland Tourism Events and Economic Development, the Ministry of Economic Development and V8 Supercars are contributing $2.2 million each to the upgrade. New Zealand Herald also reported that Auckland deputy mayor Penny Hulse said the event will be held at the raceway until 2017. Work on the track started in November 2012 and the V8 Supercar Championship races will be staged from April 12-14, 2013.
The changes to the track included a series of corners before the hairpin turn, meaning safer, slower races. 
The upgrade will includes a new race control building, timing building and corporate viewing facility opposite the main grandstand as well as the addition of overhead pedestrian bridges.
Work on upgrading the pit lane facilities in December 2012
The circuit is currently 2.82 kilometres (1.8 mi) long, having been shortened from its original combined 3.5 kilometres (2.2 mi) length when combined with the now defunct club circuit. Its visibility is low because the corridor of armco barriers is only inches from the track on both sides. It is seen as one of the fastest of all southern hemisphere circuits with the lap record at around 55 seconds and a very long back straight leading into a 50 km/h (31 mph) hairpin. In order to win on this track, the driver needs a good entry onto the back straight. Furthermore, the driver also needs to drive the car right to its full potential.
The NZ$6.6 million upgrade will include improving driver safety with revised barriers, run-off areas, tyre walls, transition kerbs and gravel traps. A new first and second line of protection (impact absorbing concrete barrier and debris fence) will be built. Some resurfacing of the raceway will occur while keeping character of the track. Plans include chicane before the hairpin on the back straight, increasing the track length from 2.84 km to 2.91 km. V8 Supercars chairman Tony Cochrane said the terminal speed of V8 Supercars on the back straight was too great. The work will improve the FIA safety from FIA Grade 3 to Grade 2.
New Zealand Grand Prix
The New Zealand Grand Prix has been held at Pukekohe on 28 occasions, the first being in 1963, and the last to date being held in 2000. Between 1964 and 1975, the NZ Grand Prix at the circuit was also a round of the Tasman Series. Winners of the NZ Grand Prix at Pukekohe include Bruce McLaren, Chris Amon, Frank Gardner, Craig Baird, Roberto Moreno, and Paul Radisich, as well as Formula One World Champions John Surtees, Graham Hill and Jackie Stewart. Källa: Wikipedia.