(click for larger image)
Although the civilian Crown Victoria is nearly identical to the Police Interceptor, the P71 comes with many features that the civilian model does not. These
features all tend to provide utility, reliability, and performance to the P71. One of these components is the roof reinforcement panel. This panel is used to help support the additional
weight of the light bars, as well as a mounting location for overhead police equipment, both outside and inside the cabin. This roof panel can also provide several benefits to the non-sunroof
equipped civilian Crown Victorias and Grand Marquis by providing additional front to back rigidity of the roof panel, as well as reducing resonance and road noise permeating through the roof in
the largest and most unsupported area of the panel.
As shown in the image above, the roof support bracket is similar to the one already found in most Crown Victorias and Grand Marquis. The difference in these panels is the large support brace that connects the front windshield frame to the roof's B-pillar support. The panel essentially acts as a large "T" brace that connects the front and sides of the roof. 2003+ Panthers with overhead display modules will have a plastic version of this panel. That panel will look like the one below.
Although this panel is similar, its only purpose is to provide adequate support for the overhead module. This plastic bracket can be modified and easily adapted to the Police Interceptor / P71 reinforcement panel. Installation of the reinforcement panel is simple. The factory support brace at the B-pillar is merely bolted in. The factory one can be simply unbolted, and the new one bolted in place. There is a thick layer of rubberized foam. The foam is flexible rubberized foam, so this will need to be replaced with a similar foam. If the goal is to reduce sound resonance, I recommend spraying the roof with rubberized undercoating after removing the support bracket and prior to installing the new one.