looking at mufflers for meaner sound

[ebbett21]

Hi there all.

Im in New Zealand and recently had a twin 3'' Diffillipo Exhaust fitted to my LS3 VT HSV Sedan. Now im running 4>1 long headers after the 3'' collector is 3'' detion pipes that go to the twin 3'' catback.
Now the system has two centre 3'' in/out mufflers and twin 3'' in/out muffler at the rear sounds ok but cant hear the note inside the car at all but resonance inside the cabin, outside its resonably deep but have to rev it hard under accerleration to get it sounding great. Im looking at ptting some hotdogs where the cats would go to get it deeper or what else could i do to get it sounding real mean, the exhaust isnt cheap cost $2000 NZD

Thanks