Any modern car that is well maintained will last far longer than you will own it. People give up on their cars because their self image needs an excuse to get a new one. A lot of the maintenance cost is time based as well: UV and ozone are destroying rubber parts even while the car is sitting.

It depends on the car, but typically you are looking at $.20/mile for fuel, and $.05 for all other maintenance (including tires).

The average new car payment is something like $550/month. The average used car is somewhat less of course. Most people are making payments. Insurance is $500/year if you have a perfect driving record, many people pay more. These costs have nothing to do with how far you drive.

A few years ago I calculated my actual per/mile cost for my car, it was $.15/month, even though I bought it new (I track every fill up, though at 46mpg my fuel costs are less than average). The car had 200,000 miles on it to spread all the fixed costs across, and had been paid off for a few years.

The point is the marginal cost to drive a car you already own is low.