Same here, I lost two of them on the motorway. First I thought I ran into a plastic bag or something got stuck to the car. Then the flapping noise stopped and I forgot about it. The next day I saw the trims missing and thought someone stole them. I went to the Ford dealer, and asked them if them if it was common that the trims give away. They told me it is here very rare, and probably it was vandalism. I asked them how much replacements costed, and the guy answered, without hesitating, or even looking at a catalog or hos computer, "36,90 each". I learned two things. 1- It is definitely a common problem, for both the Fiesta and Fusion (the replacement part is the same). 2- I am not going to the same dealer again. I got the replacement parts. They are just a bunch of plastic glued together. Not even moulded together. The bad thing is that one needs to break away the remaining clips before inserting the new ones. After that I used an epoxy glue to join the new replacements to existing rubber or plastic in the door. It's just a case of bad design. If you notice that yours are starting to come off, just get them glued as soon as possible.