I had a VZ Cross8. Big heavy bus but I put a single 3" manifolds back system and tune by Oztrack and it was awesome. A friend of mine has one too, his has extractors and tune. Mine was around 200awkW and picked up heaps of economy with the tune. HSV versions (like most HSV) are ugly but shouyld go better. My friend upgraded the brakes on his and he loves it, mine was underbraked.