Originally Posted by 1325

He likely based the darkness of the glass behind the side windows. LEOs need just reasonable suspicion; not necessarily sole probable cause. He probably let you off because he didn't have a tint meter to gauge your tint.

I rarely issue citations unless it's blatant--5% tint on the entire windshield, for example.

Edit: NY's tint statute states 70% for both front and side windows maximum, with no limit on the back window. 35% is in violation by half.