From the essay “North American Butterflies: Are Once-Common Species in Trouble?” by Scott Hoffman Black in the current issue of Wings, the official publication of The Xerces Society:
I grew up during the heyday of the American muscle car and have teenage memories of rocketing down Nebraska country roads in my 1971 Mustang Mach 1. Back then even a short drive resulted in hundreds of dead bugs splattered across the grille, so I was always washing my car to keep it clean and shiny. When I returned to the Midwest last year with my wife and two kids– now driving the a much more sensible and fuel-efficient rental car– I was struck by the paucity of bugs. These days you can drive the entire four hundred miles across the broad state of Nebraska and your car will be practically spotless when you get to the other side.
I live in East Texas, but the metric still applies: there are a lot fewer bug splatters than there were thirty years ago.