Shot through the heart
Louise shoots Harlan in the chest after he screams to her and Thelma that he should've raped Thelma. Louise shooting him is a symbol of the rage she has pent up inside of her from being raped, and it comes out in an extreme way to shut down the voice of Harlan who seeks to harm her friend.
Hal
We see Detective Hal sprinting on foot after Thelma & Louise as they drive their car off the edge of the Grand Canyon. This is a symbol of his never-ending pursuit to help people, no matter if he is pursuing them or not.
J.D.
Thelma has let J.D. into her and Louise's life because she genuinely believes he is a good guy who needs help. After he sleeps with Thelma he steals Louise's life savings and disappears. This is a symbol of Thelma's good heart being taken advantage of by the reality of the world which only wants to take.
Texas
Louise refuses to drive through Texas on their way to Mexico. Her refusal to do so is a symbol of her not wanting to go anywhere near the wound of her rape years earlier. So she avoids it completely.
Over the Cliff
Thelma and Louise decide to "keep going" instead of turning themselves into the police. They drive off the Grand Canyon's edge to their deaths. This is a symbol that they'd rather have the choice to decide how they die than be told how to live, confined in a jail cell for the rest of their life.
