Who's regulations?
Where?
Link please!
A 5 spd Insight meets federal emission standards for LEV (Low Emission Vehicle)
A CVT meets a slightly stricter standard of ULEV (Ultra ...)
A 5 spd using low sulphur fuel (reportedly Amoco premium) can also achieve ULEV.
AFAIK the "other" "_"_"EV (you fill in the blanks, there are a couple) "ratings" have to do with how long the vehicle must meet the standard. Not an "improved" rating as in lower emission values.
ZEV (Zero Emission Vehicle) means a 100% electric vehicle. The only off-the-shelf options use heavy lead acid batteries and your range will be in the 50-60 mile neighborhood. Probably do-able for the $10,000 (conversion only, you supply the car) price range. AFAIK there are no off-the-shelf NiMH or "better" hi-tech battery options. Expect to pay really BIG $ for any of these batteries alone.
CNG, LNG ( Compressed or liquefied Natural Gas) or Propane are much "cleaner" fuels but conversion is expensive and would be a custom job on an Insight. With all the "problems, limitations, and expenses that go along with it.