The rock guard over the front window on my Escape trailer has a rubber strip that runs along the bottom. The rubber strip is there to keep water from flowing under the rock guard when you are driving in the rain. This is necessary because the front window slides opens and water can be forced under the rock guard and into the trailer via the sliding window seals. The ventiliation from the large from window is great, but the rubber strip chafes the trailer gelcoat. Some tow vehicles divert the rain enough that water intrusion would not be a problem, my Jeep Cherokee is apparently not not large enough to disrupt the airflow adequately.
Since I don't expect to drive in the rain very often, I drilled out the rivets holding the rubber strip in place and removed the rubber strip. I put the rubber strip in a baggie with a set of screws, washer and nuts of the same size. I included a spare set of hardware in case I drop something. I only install the rubber strip when I drive in a significant rainfall. When driving in the rain without the rubber strip installed, only a little bit of water made it into the window track.
Another possible option is to use 3-M Anti Squeak tape applied to the fiberglass under the rubber:http://products3.3m.com/catalog/us/e...er/output_html
This the same topic discussed on FIberglassRV.com on this link. http://www.fiberglassrv.com/board/in...topic=20206&hl