TrueCar's legal woes mounted Wednesday as the online car-buying service was hit with a shareholder lawsuit alleging that it misled its investors about how it does business. The suit, filed in federal court in Los Angeles, seeks class-action status on behalf of shareholders who sustained losses on TrueCar stock since its May 2014 initial public offering, and opens up a new avenue of attack against the company, which has had a history of run-ins with state regulators and conflicts with auto dealers within and outside its network.