This is so funny -- both hubs and I thought the one (rear) plate was still all that was required. (As it is, we have old plates (think ours were issued back in 1997) from former cars, so we actually have 2, and just kept putting them on a newer vehicle.)
But we just did some research, and after 1993, the state went back to TWO plates!
Apparently, after the Spirit of America designed plates were first issued in 1986, those newer styled ones began the 2-plate requirement again (stupid rule), but I guess other plate holders with the previous design were grandfathered in until 1993.
Hubs mentioned that he's never known anyone pulled over for 1 plate -- as long as the rear plate is visible and the current tag attached. He said that if a cop wanted to pull over a car for another reason, he could use the (no front plate) excuse, to do so, but again that's a stretch. (Kind of like the seat belt law -- they can use that as an excuse, but they actually have another reason for pulling over the car.) Enforcement of the two-plate requirement might also be more of a regional thing -- I read that Cambridge is stricter about those types of nuances. Glad we don't live there, but again, we have 2 plates, so I guess it's a moot point.