TJ runs on heartwarming with bits of grief-fueled anger in between.
He tries relentlessly to get a totaled car back that has meaning to him but not so much to the rest of his family. In one instance, he attempts to buy the wrecked car back with money he withdrew from his father's account. When rebuffed, TJ decides to give the money to to Nicole so she can pay her rent and traffic ticket. Not the best method of doing so, but still well-intentioned.
The film's ending.
There is a surprisingly gentle scene in the film when Hesher is talking with TJ's grandmother. TJ's grandmother, knowing that Hesher is not TJ's "friend" due to an age difference, as TJ tried to pass him off as at the beginning, gets Hesher to talk metaphorically and philosophically, in wide contrast to his angry metalhead persona.