I noticed that with the spare heater control panel I restored, too...no notch. If I remember correctly, the plastic light bar has 2 tabs on the ends with screw holes, but the heater control can be screwed on without that light bar in place; the light bar just attaches to the bottom of the heater control plate, then to the underside of the dash. I guess if you wanted to add a light bar, you could simply Dremel out a notch and route the wires through it.Damn, now I may have to look for a light bar and harness. Just looked at my spare heater control, no notch for the wiring, and how does it attach?