Dear aydin1632,
I have said before on ESLP, that some students expect teachers of English to give a �one-sentence rule �, which applies in every case ... as with scientific subjects ... 1+1 = 2 ALWAYS.
But, language is not a science, with fixed, invariable rules. It is a living, developing body of knowledge, changing, day by day. So, it can be difficult to categorise.
"A Comprehensive Grammar of the English Language", 2010, describes �Determinatives �, (Determiners), including �Articles �, (A, The, etc.), on pages 253-287.
�The use of the Zero Article �, requires pages 274-280.
I have been through the whole chapter.
In my opinion:
QUESTION 1. a) and b) are both acceptable.
Question 1a. can be referring to a SPECIFIC situation.
"I never wear a hat when I go to the theatre, because it will obstruct someone �s view".
Question 1b. can be referring to a GENERAL SITUATION.
"Generally speaking, I never wear hats, because my Doctor says that they are bad for my scalp".
QUESTION 2. a) is acceptable.
The speaker is thinking of a SPECIFIC occasion, (when he is buying a car), and thinking of a specific car ( �the first car �).
"I never buy the first car I look at. I always look around for a cheaper car".
QUESTION 2. b) is unacceptable.
The speaker is thinking of GENERAL situations ... the several occasions when he has looked at cars.
However, b) is ungrammatical, because in this sentence, �first � is referring to one, singular item, �car � ... �cars � is not singular, but plural.
EDIT. Unless, as Almaz correctly says, the speaker is thinking of buying several cars together, in which case �the first cars� is referring to �the first group of cars� that the speaker sees.
I hope that this helps.
Les Douglas
P.S. I am half-English, half-Scottish.
but for the first one, both options are fine. Extending it to other items, the plural would be better e.g. I never wear dresses. About the car, definitely option a. I think if you meant to say you never bought the first cars, you would probably re-phrase it to something like, �I always look at a good number of cars before deciding. �
