Will anyone please make good examples using "car didn't start" and "car wouldn't start" that illustrate the difference clearly between "did" and "would"? I'm having trouble with these words, especially when the subjects are things, not people.

Thank you in advance,
There is an overlap. Away from this overlap, "wouldn't" may have a stronger sense of repeated efforts and repeated failures: "No matter what I tried, the car wouldn't start."
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I know that cars can't refuse to do things, but when you say that your car wouldn't start, it comes close to saying that your car refused to start, as if you had had an argument with it! My car wouldn't start therefore expresses some degree of frustration for you.

Compared to that, My car didn't start is a pretty simple remark.

Yes, that's why I felt uncomfortable when I see "would" being used with the subject of things: they don't have mind or will.

So, my understanding is, all in all, there were repeated tries and failures, and the car even seemed to be unwilling to get started, so in that case it's proper to say, "my car wouldn't start," rather than "my car didn't start."

Thank you always,
If you can't get your car's engine to turn over, you probably would say " I couldn't get my car started".
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