On Tuesday, I ordered the bits to make the exhaust (it's all 2½" diameter stainless steel) - they turned up today, so I thought I'd have a go at making it.
First of all, I had to trim the original down-pipe.
The top part of the down-pipe was cut at the 63mm diameter line.
I then welded a 90° tube to the down-pipe flange, and the catalytic convertor (a sports cat). Later on, I welded two 90° tubes together to make 180°, and pushed it into the other end of the cat.
Then, I put the box in roughly the position I wanted it.
While doing this, I realised I didn't have quite the pipework I need - so I'll have to order some more.
This end is pretty close to the rear section hinge.
I'll probably put a braket near here to prevent it from moving into this.
There's plenty of space above it though! I'll put some aluminium plate above it to protect the body.
I actually had a lot of fun doing the exhaust!