The upper plug wires need to enter through the rear baffles. I purchased these nifty two-piece grommets from Aircraft spruce (darn little buggers are $20 a pop!). I used the unibit to drill a couple (overlapping) 7/8" holes and then drilled the bolt holes above and below that secure it in place.
Plug wire grommets installed at rear baffles. Shown on front for clarity
This one is properly locate on the rear side of the baffle