I don't think I fully understand the purpose of mud flaps.  While driving behind a tractor trailer, no less than 16 billion rocks are flung at my windshield.  There aren't even that many rocks on the road to begin with.  It's almost like trucks create rocks.  So what exactly is the purpose of a mud flap?  Would my car get hit with more rocks if trucks didn't have mud flaps?  I find that hard to believe. #food