Is there a plug or access hole to route the wire harness through the fire wall?
Any other tips would be a great help. Thanks.

 

There's a convient little grommet that a sheilded cable goes thru the firewall below the pedal ***.
I ran my turbo timer wires thru it and when I picked up my XZT, I ran that thru thru the same grommet.
I just slit the outer flange of it a bit more. Worked great.

 

No hole with a manual, easy with an auto. I'd drill a hole and use (I'm sure quad supplied a grommet) and go that route. You might drill a bigger hole for future uses and use your own grommet.

 

There's a big rubber boot where the main harness comes into the cab on the drivers side. You can fit more wire through there than you'd ever need to install anything (even with a manual tranny).