They stand for Opel Performance Center (the German counterpart to Vauxhall's VXR line) and they adorn performance versions of the Corsa, Astra and Insignia. The latter is undergoing a bit of a refresh and is expected to debut at the Frankfurt Motor Show in a couple of weeks, but you don't have to wait that long as our intrepid spy photographers have caught it in the flesh outside an Opel facility in Germany.
Spied here completely undisguised in Sports Tourer (read: wagon) form, the Insignia has had a few nips and tucks performed, but we'll be more intrigued to see what it's got under the hood. The current model packs a 2.8-liter twin-turbo V6 driving 325 horsepower to all four wheels, but rumors suggest that the OPC (yeah you know me!) could have as much as 400 hp up its sleeve. That would make this one heck of a sleeper – especially in wagon form – and only make us pine for a more potent version of its twin Buick Regal to roam our highways, too.