In the middle it was attached to the rear link arm stays.

Further back, you can make your own bracket under the gearbox.

In front, you can either weld your own bracket from e.g. square tube or buy for our beam (AS-005002-04) which is welded between frame beams.

If it is enough with a shorter exhaust plate that only covers the engine, you can find it here  AS-005002-01