The Carlton is more GM than Vauxhall. It has a Corvette gearbox, and tuned Vauxhall engine with new pistons, rods and crankshaft and two turbochargers. The rest was pretty standard upgraded fare.
The VXR8 is more australian muscle car than Vauxhall though. It has an american engine, a similar gearbox and a 15 year old chassis.
The Carlton was a one off really, I'd never put it in the same league as a VXR8, it's much much better.
"C20 LET bang"