While Volkswagen's admission that does not specify all the makes and models affected, AustralianCar.Reviews has compiled the following list for Australian-delivered vehicles:

• Audi B8 A4 (CCWA/CDUC);
• Audi A5 Coupe (CCWA/CDUC);
• Audi A5 Cabriolet (CCWA/CDUC);
• Audi A5 Sportback (CCWA/CDUC);
• Audi C6 A6 (CDY);
• Audi C7 A6 (CDUC/CDUD/CGQB/CRTE);
• Audi C6 A6 Allroad (CDY);
• Audi C7 A6 Allroad (CDUD/CRTE);
• Audi C7 A7 Sportback (CDUC/CDUD/CRTE/CGQB/CVU);
• Audi D3 A8 (ASB);
• Audi D4 A8 (CDT/CTB);
• Audi 8R Q5 (CCWA/CDUD);
• Audi 4L Q7 (BUG/CASA/CCJGA);
• Audi Mk.2 Q7;
• Porsche Mk.1 Cayenne (CASA);
• Porsche Mk.2 Cayenne (CASA/CRCA/CRC);
• Porsche Macan (CRC);
• Porsche Panamera (CASA);
• Volkswagen 7L Touareg (CASA); and,
• Volkswagen 7P Touareg (CASD/CJMA/CASA/CRCA).

In its second violation notice, the US EPA described how the defeat devices could sense when the vehicle was undergoing an emissions test and operate in a low NOx "temperature conditioning" mode to satisfy emissions standards. However, "[a]t exactly one second after the completion of the initial phases of the standard test procedure, the vehicle immediately changes a number of operating parameters that increase NOx emissions... up to nine times the EPA standard, depending on the vehicle and type of driving conditions.'

It is unclear what actions Volkwagen will undertake so that these vehicles can be rectified to comply with their claimed emissions standards. AustralianCar.Reviews understands that the 3.0-litre turbo-diesel engines for these vehicles already have Selective Catalytic Reduction (SCR) systems which inject an aqueous urea solution ("AdBlue") into the exhaust gases to convert NOx into gaseous nitrogen and water. While the shortcomings of Volkswagen's emissions reduction measures are unclear, recognised limitations of SCR include:

• Limited NOx conversion at low-load driving conditions (for vanadium catalysts); and,
• Limited effectiveness in urban driving conditions where exhaust temperatures are often below the required 180 degrees Celsius threshold for the urea solution to vaporise into ammonia.

One possibility for reducing NOx emissions is the fitment of a lean NOx trap (LNT) which absorbs NOx by using alkaline earth or rare earth oxides such as barium oxide or cerium oxide, in conjunction with noble metals, to form nitrates such as barium nitrate. While BMW has used SCR and LNT systems for US versions of the BMW 3-Series, 5-Series and X5, retrofitting a LNT would pose packaging, cost and technical difficulties.

The Kia JF Optima shares its platform with the Hyundai LF Sonata and 50 per cent of its body is constructed from Advanced High Strength Steel (AHSS), a 150 per cent increase on the TF Optima, which contributes to a 50 per cent increase in torsional rigidity and an 8.6 kg lighter bodyshell.

As standard, active safety technologies for the Optima Si and GT include Autonomous Emergency Braking (AEB), Advanced Smart Cruise Control (ASCC), a Lane Departure Warning System (LDWS) and High Beam Assist (HBA).

For more information, see our 2015 Kia Optima review.

As standard, the Range Rover Evoque Convertible TD4 has a fifth-generation Haldex all-wheel drive system which consists of an electronically controlled and hydraulically actuated multi-plate clutch. In normal conditions, drive is primarily directed to the front wheels for maximum fuel efficiency. If a loss of traction occurrs or is anticipated, the centre coupling engages to direct torque to the rear wheels (up to a 50:50 front:rear torque split).

The Evoque Convertible Si4, however, will have Land Rover's 'Active Driveline' which is manufactured by GKN Driveline. Under low loads or when coasting, the Active Driveline system decouples the rear axle to minimise parasitic losses and improve fuel consumption. Since Active Driveline disconnected the all-wheel drive components from the gearbox, rather than the central coupling, parasitic losses could be reduced by up to 75 per cent. The Active Driveline system also includes a torque vectoring function.

For more information, see our Range Rover Evoque preview.

Other changes for the 991.II 911 Carrera range include updated styling, the new Porsche Communication Management system with a seven-inch touchscreen and, as options, rear axle steering and a front axle lift function which can increase ground clearance.

For more information, see our Porsche 991 911 Coupe review.

Compared to its NC MX-5 predecessor, the Mazda ND MX-5 is 105 mm shorter (at 3915 mm), 10 mm wider (1730 mm), 10 mm lower (1235 mm) and has a 15 mm shorter wheelbase (2315 mm). With a kerb weight of 1009 kg, MX-5 Roadster with the 1.5-litre engine is 91 kg lighter than the NC MX-5 due to its more compact design, lighter soft-top roof and the use of aluminium for the model's bonnet, boot lid, front fender and bumper reinforcements.

Standard features for the MX-5 Roadster include a six speaker sound system, air conditioning, cruise control, LED headlights, black cloth seat trim and push-button start. The MX-5 Roadster GT, however, adds a Bose sound system and Mazda's 'MZD Connect' system with satellite navigation and Internet radio integration.

For more information, see our Mazda ND MX-5 review.

BMW refers to the passenger cell for the G11/G12 7-Series as its 'Carbon Core' since it combines industrially manufactured carbon-fibre-reinforced plastic (CFRP) with steel and aluminium. Combined with an aluminium bootlid, the combination of these materials contributed to mass reduction of up to 130 kg relative to the BMW F01/F02 7-Series models.

As standard, the G11/G12 7-Series has:

• Self-levelling air suspension (front and rear) which also enables the driver to increase ride height by 20 mm for rough roads or ramps; and,
• BMW's 'Dynamic Damper Control' which can adjust damping resistance according to the selected drive mode (Comfort, Comfort+, Sport or Adaptive), driving style and road surface.

For more information, see our BMW G11/G12 7-Series preview.

Whereas its E84 X1 predecessor shared its platform with the E93 3-Series Touring, the F48 X1 shares its UKL architecture with the BMW F45 2-Series Active Tourer and Mini F55/F56 Cooper. Compared to the BMW E84 X1, the F48 X1 will be 115 mm shorter (at 4439 mm), 25 mm wider (1821 mm), 53 mm taller (1612 mm) and have a 90 mm shorter wheelbase (2670 mm).

For the X1 xDrive variants, the xDrive all-wheel-drive system consists of a single-speed bevel gear in the front-axle drive unit (a power take-off) and a rear-axle drive unit with an electrohydraulically controlled multi-plate clutch. In normal driving situations, however, power is directed to the front wheels.

For more information, see our 2015 BMW F48 X1 preview.