Symbolism in fiction can be broken up into two categories. One is based on societal preconceived ideas that the reader brings to the table, such as a four-leaf clover might mean luck. The other is based on things established within the story, such as the original Cinderella where her mother is buried under a weeping willow, and her fancy dress and such come from its branches.
I like the second kind. I like that this car carries a lot of weight of the relationship between Jay and Bruno.
