OPC, which stands for Opel Performance Center, is the name given to models developed through by GMs official in-house tuner in Europe. The OPC cars typically feature minor engine and handling mods as well as styling and performance upgrades such as bigger wheels and sporty bodykits. In the UK, the car will likely be known as the Vauxhall Insignia VXR.
The oversized wheels and cross-drilled brake discs of this latest prototype suggest that this is a new performance variant of the standard Insignia. The latest images aslo reveal the car will feature a Brembo developed brake package. A V6 badge at the rear of the car, meanwhile, confirms that the 260hp (194kW) 2.8L engine from the standard model will also be used in the OPC, however, the addition of a turbocharger system could boost power to levels beyond 300hp (225kW). One final clue is the heavily masked front-end, which is likely hiding a set of new intakes.
Previous reports suggest that a new AWD system will be fitted to the car to improve handling, while stiffer suspension and an uprated steering system will also improve the cars track performance. The AWD system is the same torque-splitting electronic differential used by Saab for its 9-3 Turbo X.
Source: motorauthority
I am not sure I totally agree with ts: Opel Insignia OPC with Brembo brakes | No Speed Limit