If they can't be functional they can at least look functional. From a distance when the strakes are in shadow the black plastic gives the appearance that the indents are opened up. I like the look of that and have thought about removing the strakes and cutting open the front of the indent. If there is stuff that can be seen then I suppose the opening can be blocked off with a screen. Granted this would mean the indents would be all show but the strakes are like that already. I'm just not keen on taking a can opener to my fenders. Any volunteers?