Step-by-step explanation:
The sentence from your question should be:
The car I just bought needs all kinds of repairs.
- In this case, if we are looking for an adjective clause, that would be ''I just bought''.
The adjective clause is describing the noun in the sentence and in this case, the noun is ''The car''.
This type of clause is considering a dependent clause and usually, this type is not changing the meaning of the sentence.