Apologies to Oz for continuing on about speakers instead of doors.... But, I lifted a pair of kick panels out of a HQ ute which were the originals and they had four little indentations on the rear of them which corresponded nicely with the 'dimple' in the body metal behind where the kick panel is attached. I thought that the indentations provided a screw template for speakers. The dimple provided space for the cone of the speaker. Did the optional Airchief 13 radio for the HQ have balance control?