[fpv_gtho]

You can but you cant use some of the componentry, namely the tyres. Team Dynamik when they were caught were fined for illegal testing of the cars, tyres, ECU and a couple of other things. You can replace all those parts on something that isnt registered as a V8 Supercar, but it just restricts your feedback, and the rest of the feedback wont be 100% accurate. Still possible though.