They were saying, IIUC, that it could be that the same amount of bugs are splattered across a larger number of cars, so that if you look at any one car, then it looks like less bugs.
15 years later they no longer do that, just on that road in particular. I don’t know if it’s evolved behavior or learned, but they absolutely changed.
That said, it’s fun to imagine that we just selected against insects that hang out by the highway.
https://www.npr.org/2013/03/22/175054275/birds-evolve-shorte...
Insects still get hit with aerodynamic cars, but the blows are glancing and less likely to cause a “burst”.
(Although, TBF, the Lambo's wing and aero package adds a lot of drag in exchange for much greater downforce)
[1] https://ecomodder.com/wiki/Vehicle_Coefficient_of_Drag_List
"The research also found that modern cars, with a more aerodynamic body shape, killed more insects than boxier vintage cars up to 70 years old."
Source: https://en.wikipedia.org/wiki/National_Maximum_Speed_Law