My ancient car wasn't getting much use and had reached the point where the $$$ needed to make it reliable and safe again weren't easily justified. I was talking recently with friends who live in places where sprawl is the norm and getting anywhere without a car is impossible. At times I felt like I might as well be talking to someone on Pluto.
In most parts of the Chicago, bikes and public transit can get us around pretty well. Public transit has been a priority in my choice of jobs. I would not accept a job in a location where bikes or public transit are not a viable commute option.
For me, the answer "just buy a new one" doesn't sit well. A lot of resources go into making a car and transporting it to a dealer. A lot of energy is consumed by the average car during its lifetime. A lot of time and money are spent on getting a car to and from the mechanic and getting it serviced. I've experimented with how to get by without, using bike, bike plus trailer and public transit. Now that we have an I-Go location in Beverly, it's a lot easier when a car is the only workable answer. (Thank you, I-Go!)
One friend, who drives a Chevy Suburban, pushes the idea of an SUV or crossover. Putting another SUV behemoth on the roads is definitely not the answer for me. I don't believe that putting more tanks out there makes the roads safer.
In car-pedestrian accidents, the pedestrian is much more likely to die or be severely injured if hit by an SUV than by an average-sized car. Studies are being done to modify designs to improve pedestrian safety, but that doesn't change basic physics: force of impact is directly proportional to the weight of the object. Heavier, taller vehicles hit with more force in ways that are harder to survive. They make the roads less safe for pedestrians, cyclists, occupants of smaller cars, etc.
I've donated the car to charity. It's nice to have more room in the garage and free up money for other things. Even though I haven't had a car payment in years, the cost of insurance, license plate, city sticker, gas and minimal maintenance adds up. That's roughly $800-1000 a year that I can spend on other things. That money will more than pay for as many Metra, CTA I-Go and Pace trips as I need to take, with cash to spare for bike maintenance. Having one less car in traffic is a beautiful thing.