Cause for concern ??

it covers the screws for a reason its cheap buy new and replace it

The road wind was blowing one of mine out . I used a latex caulk and reinstalled it. No problem in the last couple years. Water does seep in around those screws and this gives some protection against that.

THAT system, complete with the plastic insert, is a manufacturer's affordable method of covering the joint-screws, and to give the whole thing a "finished" look.
I replaced all the screws with stainless steel screws (one by one), and replaced the insert (new insert stays on). I also removed the thin caulk on the upper edge of the aluminum strip. BUT, I used the best caulk/sealant that I know of,....3M Marine Adhesive/Sealant/Caulk #5200 Fast Cure. AND, before I installed each new SS screw, I applied a small amount of PEMEX Gasket Maker goop to the screw threads, and when I screwed them in, a little bit of goop squished out. Everything there is sealed permanently (my guess).

Oh, and yes, IMO it would not allow water to come in, even if the insert was not installed.

Probably this stuff linked below. At least mine was 1 inch wide. Your right, just covers screws, but also keeps some junk out. Looks a lot better with trim in than without. Being thin vinyl it gets stretched out of shape by just being exposed to weather after awhile.

I wouldn't put stainless screws in. They are usually much better in most RV applications, but not in this case IMO. When you use the cheap zink screw, you have also just screwed in a "moisture" indicator. Later on if you ever have to track down a water problem, you can pull a few screws and look at the zink coated screw and will be able to see how much rust is on the screw to have better indication where water might be getting in. One of the few times when "cheap" pays off IMO.


http://www.amazon.com/Camco-25202-Vinyl-Insert-White/dp/B0006JLW5M