Offroad-Express

Does my exhaust need to go all the way to the back of the vehicle.
Can I for instance dump it half way down. I realise that this is a bad idea with a petrol engine due to the possibility of carbon monoxide entering the passenger compartment, but does the same go for diesel?

Alternatively can it be turned out the side at the earliest opportunity?
This would reduce ground clearance, but it's a tow wagon and for beach launching so the ground clearnace is not that important.

It seems the only stuff I can find on the Web is related to noise and/or emissions.

Just interested to see what effect the shortest possible exhaust may have on performance, if any.

My understanding is that exhaust tip must exceed edge of body and end behind the rear most opening window. But at the end of the day its at the wof inspectors discression.

yup rules say 150mm beyond the rear most passenger compartment...
Or something like that..
My WOF man has let me get away with just past the rear passenger door....
But I plan on moving to out the back as its too loud...Esp in the summer with the window down. Something to think about if its a daily driver.

5. The exhaust system is so constructed that emitted heat
or fumes are likely to harm vehicle occupants, eg the
exhaust gases are not directed away from the perimeter
of the vehicle’s passenger compartment (Note 6).

Wording from the VIRM.
(note 6 is about wastegate screamer pipes)

So basically in regard to where pipe exits, generally its best to exit beyond the perimeter of the cabin, and behind the rear most door/window where possible.
If you have an idea, ask your wof inspector and he'll guide you in the right direction