When I bought my ZXW the antenna was really noisy in the wind at freeway speeds. When I checked it out the rubber around the Spring at the base of the antenna had literally started to flake off and it was whipping around like crazy.
I decided to try to replace the rubber instead of buying a whole new antenna. I had some 3/4 inch diameter heat shrink from Home Depot left over from my Subwoofer power wire installation so I cleaned off all the old rubber and used my heat gun to add the heat shrink. And done. You can use a Black Paint Pen to black out the letters if you buy heat shrink that has them.
I also added a little bit to the top to replace the end bit that fell off too. I put on extra and just cut it off where I wanted it to get the right size. It's now been a month and it's holding up well even in the Florida sun and heat.
Much Cheaper than a new ford Antenna and After Market ones rust easily here by the beach. Here are some Pics