What are the motifs in Driver's Ed by Caroline B. Cooney?

Most of the conflict in "Driver's Ed" centers around the issue of taking responsibility for one's actions. Morgan and Remy try to pretend that they are still innocent, good kids, but they are losing sleep and hating themselves more every day for killing Denise Thompson. Owning up to their crime to Mr. Fielding, Mr. Thompson, and their parents helps Morgan and Remy begin to emotionally heal.