As emiller states. The G8 is based on the highly successful Holden Commodore as used in the Australian V8 Supercar series - a 2 Marque 'Touring Car' race series (Holden Commodore and Ford Falcon) It is also sold in the UK as the Vauxhall VXR8 - the latest version as the Bathurst S with a WP 190 supercharger & 552 Bhp 6.2 litre ( 378 cu in ) Corvette engine. So it is a bit of a (highly potent) Mongrel - Australian Body, US engine & British Knowhow!