The car broke down and had to be towed from the side of the road. -- This is a very normal thing to say.
On no - your front left headlight is broken.
I agree that a car is too large to be "broken" though parts of it may be.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.
And when it keeps breaking down it's sold for scrap and taken to a breaker's yard;... where it's broken up. (Don't blame me, I just speak it! )