Use the phrase "go into detail about" to mean explaining or expressing a lot of details about a topic. When someone has only given a general overview of a topic, and you want to hear more detail about it, you can ask the person to "go into more detail" as in the example above. You can also say that someone didn't go into a lot of detail.
He didn't really go into a lot of detail about what he was looking for, but I think it might be something like this.
In this example, you see that the phrases "didn't really" and "a lot of" are used with "go into detail about". Remember that you "go into detail about" a topic, not a thing. So it's a little strange and incorrect to say "go into detail about her car". Instead, you would say:
She went into a lot of detail about where she bought her car and how much it cost.