I like form to follow function. Few things irk me more than non-functional styling flourishes that look like they should do something useful, but don't. Take non-functional vents, for example. Whether on a hood or fender, vents should, well, vent.
Another irksome detail that recently caught my eye - and ire - is the small piece of black plastic found underneath the headlights of some models. The two that come immediately to mind are the 2013 Ford Escape and the 2014 Jeep Grand Cherokee. The Jeep gets a partial pass since on models equipped with HID lights, the strip covers the retractable headlight washer nozzles. As for the Ford, every model from the entry-level S to the top-line Titanium has the plastic strip but none have headlight washers. The same criticism applies to the new Buick Encore, which also has the black plastic piece below its headlights.

I actually find these worse than the fake fender vents. At least with those, you can argue that they make a stylistic difference. These black plastic pieces? No useful purpose that I can see. To me, they’re unsightly and indicated some laziness on the part of the designer. Why not just make the headlight housings fill the space?
I’d love to hear the reasoning behind the use of these plastic strips. Do they serve an engineering purpose? Or are they just there because of some last-minute styling change made after the order for the headlight housing was already in?