Die OPC Extreme was inderdaad niet straatlegaal. Het was een showauto en verder compleet nutteloos (er was er ook maar één):
The Astra XTreme, a concept presented at the 2001 Geneva motor show, was a single-production V8 powered Astra based on the G-series Astra DTM. Like the DTM race car, it featured a 4.0L V8 engine, producing 444 hp (331 kW), gull-wing doors supported by gas struts, carbon fiber panels, and race-specification interior with five-point seatbelts.