If the car's brakes don't work due to a defect, you are not liable at all.
And if you show reasonable due diligence, that is regular maintenance, the same applies doubly so.
Beyond that, I've seen a lot of accidents, and none of them were the car's fault.
All were literally human error, or external factors. EG, deer leaping on to road, too many frogs on the road, etc
Morally perhaps but if you drive into the back of me because your brakes have a manufacturing fault I would still expect you to pay for the damage. The manufacturer may then be liable to you but that that is your business.
If you are driving a car and an crash occurs due to a manufacturing defect, you'll probaly not be found criminally liable.
This becomes super important if someone gets injured or killed.