The thought crossed my mind to go car-free after retirement, but one problem is my friends are geographically spread out. It would be difficult to visit or even arrange get-togethers at places we like. Also I think there's a grandchild coming in the next 2 years whose parents live about 15 miles away, so I'm figuring on lots of back and forth there.
But if going car-free is doable, it's definitely a big plus for a frugal lifestyle. I remember the classic book "Living Poor with Style" (title later changed to "Living Cheap with Style") where the author said no truly poor person should have a car. That seemed almost anti-american but it really stuck with me, and I think he's right.