Hey guys, so im installing a stereo in my 89 xj and there is this black plastic slot that the back of the stereo sits in. Its up near the firewall.

My stereo is gonna be all amped up so im gonna have 6 rca cords runnin through there and they dont all fit in the little space between the plastic slot and stereo. Does anyone know what this slot does?
At first I thought it was an air duct for the heater.. but i drilled a little hole and no air comes out.

I think im gonna rip it out, any suggestions?

 

As far as I know that is just a support for the radio and is not needed.

 

Change of plans, i think it is the duct for the defrost.. so i just cut out a slot out of the top of it (it still holds air and supports the radio).