yeah tuna, leave it out the back mate. And what hilux model is it? your better off if your looking for power to go to someone who tunes deisel exhausts and they will already know what way to go to get the most power. Depending on if its turbo deisel/ naturally asperated etc... 1 single 3 inch mandrel or split it and run 2 smaller ones. I dont know im not really a deisel guy, but they know just what to do. Then get a D- Tronic chip for it
![Smiley](http://www.ausfish.com.au/yabbfiles/Templates/Forum/default/Original%20Smilies/smiley.gif)
. Also exhaust fumes cause rust aswell under your tray. Not to mention the deisel puffs of goodness.