This is a clause having a subject and a verb that relates to something else in the sentence.

The type of clause described in the question is a Relative Clause.

Explanation:

A relative clause is a group of words having a subject and a verb that relates to something else in a sentence by describing, adding further information, or modifying that “something else.” Thus, a relative clause functions as an adjective, that is, it modifies a noun. This type of clause should always be part of a sentence because it does not express a complete thought on its own.

Here's an example of a sentence with a relative clause (underlined):

The board games that I borrowed are not in excellent condition.

“that I borrowed” is a relative clause because it modifies and relates to the noun “the board games” and it has a subject, which it's the relative pronoun “that”, and a verb, which it's “borrowed.”

to eliminate ambiguous remote or broad reference it is necessary to focus on anaphoric reference. by definition "anaphoric reference means that a word in a text refers back to other ideas in the text for its meaning." the references should be clear and leave no room for ambiguity.

in the first case the pronoun it probably refers to the car but it has not been mentioned before so we should replace it for the car. in doing so the statement becomes clear.

in sentence number   two   the pronoun he refers to charles dickens the author. yet, the first half of the sentence is about the book a tale of two cities. to repair this it would be better to rephrase the first half : after i read   a tale of two cities by dickens, he so as to remove the remote reference.