Answer :
We have a red car would be correct.
Explanation :
- "A" is used before singular countable nouns when you are referring to a general or non-specific item for the first time.
Example: A cat walked across the street.
- "An" is used before singular countable nouns that begin with a vowel sound when you are referring to a general or non-specific item for the first time.
Example: An apple fell from the tree.
- "The" is used before singular and plural nouns when you are referring to a specific item or something that is already known or has been mentioned before.
Example: The book you borrowed is on the table.
- "The" is also used before superlative adjectives and when referring to a whole class of people or things.
Example: She is the tallest girl in the room. The rich face unique challenges.