I installed a CB antenia on my truck this weekend. I have always been kinda a nut about installing them in the center of the vehicle as you get much better broadcasts and reception that way. I attached this one to the luggage rack instead of drilling it through the roof like I did my station wagon.
The luggage rack bars have plastic endcaps, so they are non-conductive. I am not sure if this will really work, but I wanted the bar to be electrically connected to the rest of the truck for a better ground-plane for the antenia. So I by-passed the plastic end caps with some wire.
Here is one side of the luggage bar where you can see the wire connecting the bar to the truck. I did this on both sides. I have good conductivity, so I am hoping it works.
The clamp wasn’t biting through the paint, so it was isolated from the bar I worked so hard in modifying. Here you can see I snipped off a #6 screw and placed it between the clamp and the luggage bar so it digs through the paint. It seems to work so far. Time will tell if it will work itself loose or not.