For those who advocate car sharing programs, I didn't find those very helpful.
I am a member of both Autoshare and Car2Go, and they become increasingly expensive. If you want to take a short trip and come back right after, for a total of less than 2 hours, yes, it is probably a good idea. But for those who need to head somewhere for most of the day, the math starts to collapse as those programs charge more than $80 for usage exceeding a certain number of hours, and you only drove it for 25 minutes to Richmond Hill in the morning and come back in the afternoon, and leave it parked for the entire day. I end up renting cars in the traditional way 95% of the time, as it turns out, the occasions you need to make a quick trip somewhere and come back immediately is very very rare.
Yes, it is still cheaper than to own a car - but the level of convenience is different too. With you own car, you can use it any time you want, not subject to availability, and you have the luxury to drive to get grocery, instead of carrying all the heavy stuff in your hands and walk for 20 minutes. For example, I like to shop at the T&T, but the one on cherry street has no public transit access. The only way to go there is driving (for only 10-15 minutes).
I don't like driving and 'd like to envision Toronto as a completely car independent city like Paris or New York - but it is not. The city doesn't offer nearly adequately convenient, to be say affordable public transit for people who choose not to have a car. Even those who never have a car, life quality of life is highly constrained by not having a car (often choosing not to go somewhere they want to within the city proper due to not having a car/transit taking too long).