Battery looks good but won't start intermittently. Most of the times she starts but just started giving me trouble. Any help ?

 

You are under warranty, have the dealer worry about it. What happens when it will not start, does the starter not turn? Or does the starter turn and the engine will not start? If it will not turn, you likely have a mostly dead battery and need it and your charging system checked out. That can be done at Advance Auto for free if a Lexus dealer is too far away.