Just had a look and this is there summary
"The 3 litre 4 cylinder turbo diesel D22 Navara Ute bolt on system includes a 2.5" cat back engine pipe, a 2.5" connecting pipe & a rear muffler/tail pipe assembly. This system bought the peak torque back by 350rpm"
If you were quoted $1000 for this I would say its a rip off, you can get a 2.5 turbo back system from 'Exhaust Shop' in Victoria for $420 (supply only) would'nt cost too much to get it fitted.
STC