Mixed Signals

What is with manufacturing automobile turn signals and headlights together?  The taillights are bad enough.  I usually follow at a distance safe enough to get irritated with (but am in no danger of hitting) the half witted driver who turns without... oh, is that faint glimmer a turn signal?  Staring into the headlights of an oncoming minivan, slowing inexplicably... Ah, my dazzled eyes just caught a fleeting flash, didn't it.  Give me the old bolted on bug eyes!  Give me the hand signals!  No, not that signal...