> One final factor that can impact how long your car lasts is good, old-fashioned luck. Unfortunately, luck is one factor completely out of your control. You have control over the way you drive, but not the way others drive. Even if you are a defensive driving expert, you can still find yourself involved in a car accident.

So the numbers are calculated including traffic collisions in the life span calculation.

I wonder what the actual number is if you exclude traffic collisions? "How often should I expect to have to replace my car" and "How long should I expect a car to last" aren't quite the same question.