I also have been wanting to “do my part” environmentally - and when the Gov. offers me $4500 for the old boat, it is rather tempting.
Doing your part may just be living with as economical mode of transportation as possible which may or may not include a Prius. I wouldn’t look at a Prius as an automatic entry to “conservation” heaven…only if it happen to serve your needs otherwise. And as with all choices, take long drives and try to duplicate the use you will give it to avoid surprises.
In my opinion, that’s the best way to “do your part”. Buy an SUV if you have a need, buy a Prius if you have a need. If everyone based their car choices upon needs instead of whims, we’d all be “doing our part”.