What negative trait has Nick discovered in Jordan Baker? When does this appear?

Nick discovers that Jordan is a liar.

Jordan Baker instinctively avoided clever, shrewd men, and now I saw that this was because she felt safer on a plane where any divergence from a code would be thought impossible. She was incurably dishonest.

This becomes apparent to Nick when Jordan lies about leaving the roof down on another person's car.

When we were on a house-party together up in Warwick, she left a borrowed car out in the rain with the top down, and then lied about it —