Hi Gizmo,
I can't remember if it goes between the body and rack or not, but I would put it there just to keep it out of the way.
There is a small spring steel clip that holds the wires to the rear facing leg of the front subframe - I think they are the same as the ones that hold the brake pipe to the front of the subframe for the left wheel.
But..... depending on what exhaust you have, you may want to move the wires to a cooler location...
Cheers, MD.