Irrelevant to you perhaps, however they do make marked cars approaching from the rear at night harder to spot & differentiate from civilian cars. They also make oncoming marked car daylight approaches harder to pick out at distance (assuming their radar's off of course). Not impossible of course, but more difficult.

But as you say, being watchful is the most important bit. (/me prepares for 60 mile commute home)

-Zeke
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