I picked up the custom exhaust system from JB's. They fit perfectly, and also look pretty good. JB charges $1200 for these which is pretty good considering I was budgeting $1500 for a one-off system. I will also need to make or buy a heat shield/cover for the pipe, which is another registration requirement. The pipework is all ceramic coated steel up to the single outlet, and polished stainless steel after that.

Here is the rear flange. Queensland Department of Transport regulations require exhaust systems to exit either from the driver's side, or the rear. So for registration, the pipes will have to exit out the back. Let's hope the rear exit pipe doesn't fall off after registration. I'll have to fit a nice side exit pipe then!