Never had a car. After knowing what my fellow friends who have cars spend a month on them, I'm amazed. Insurance, car payments, etc. All that money, could have bought new bikes!
Seriously though, it depends on your needs. You could keep a car and try not to use it. If you live in the city, especially Chicago, there's no need for a car - the CTA runs well if you need it but I ride all year round. If I have to go to the burbs, which I have once in a while, I ride it - makes for a good long trip. You could make a weekend out of it (visiting the folks).