Right, sorry, grid-type defoggers for square A-bodies starting in '74, not '76. Verified per FPC. Wonder what I had in mind? Something to do with the glass, but now can't get a spark out of that neuron. :shrug:
As a matter of purely academic interest, legally speaking, there is no such NY state requirement. Per 49 U.S.C. 30103(b)(1), States may regulate the use of vehicle equipment, but they are prohibited from enacting vehicle equipment requirements, prohibitions, or design/performance requirements that differ in any respect from any provisions of any applicable Federal Motor Vehicle Safety Standards (49CFR571.101 et seq). In practice, this means states may enact standards more permissive but not more stringent than the Federal standard. State vehicle equipment standards are legally null and unenforceable to the extent they are more stringent or materially different than the Federal standard So, for example, because FMVSS No. 108 says rear turn signals must be visible from 45° inward to 45° outward of their axis and may emit amber or red light, states may not require that they be visible 60° out to 60° in and emit only amber or only red, and may not require that they emit green or white or anything else. Likewise, because there is no Federal requirement for backglass defoggers, states aren't permitted to require them. This Federal preëmption is predicated on the philosophy that a significant purpose of the Federal standards is standardisation, so a vehicle legal to sell in one state is legal to sell in all states.
That did not stop NY from placing such a requirement on their books, and it has not stopped various other states (California...) from attempting to promulgate vehicle equipment standards more stringent than the Federal standards. Occasionally there were tiffs between the Feds and such states; other times automakers just complied with the spurious state standards rather than go to the hassle and delay of challenging them (and sometimes the tiffs went the other direction, as when the Feds were upset with OR and WA for those states' very sensible revisions to their headlamp requirements in the 1970s).
So: Yes, NY has such a requirement on their books, but it's null and void, but Chrysler complied anyhow.
Just kidding..... It happens so rarely.