Fond of rumpots, crackpots, and how are you, Mr. Wilson?

I know people who use, and are happy with, Zipcar. One of the main things is: are there Zipcars near where you live, and are they available at times when you want to use them? You're in Watertown IIRC, and I don't think they have Zipcars out that way--you mostly find them in Boston and Camberville.

Another thing you might want to think about is the limitations that not having a car will place on your future employment. If you have a car, you can always leave it at home and take the T, but if you don't have one, you're locked into what you can get to on the T, which limits your options considerably, or you're forced into "HOLY CRAP I START WORK IN A WEEK AND I NEED TO FIND A CAR NOW", which will almost assuredly lead you into buying a suboptimal car.

What's wrong with Harold the Hoopty Car, anyway?