I found a neat way of mounting exhausts on kit cars using the mini rubber mount from the middle of the system, I used them as below on the underfloor system on my old cobra but they would lend themselves to the side of the roadster like in skovs case.
Take the exhaust clamp and drill an 8mm hole in the middle
Thin down a 5/16 unf nut an push it into the clamp. Its not metric children.
Then screw the clamp onto the stud and bingo.
You will only need two rivnuts in the vertical tubes on the side of the roadster and no brackets are needed. The exhaust will hide the whole thing. Just trim off the excess thread.
Bob