What are some symbols in Twilight?

Probably my favorite symbol from the book is the apple.  I'm not sure which edition you are reading from, but the original cover had a picture of an apple.  It seemed like a weird cover considering that the word "apple" is used only 3 times in the entire text.  It's also a book about vampires, so an apple seems like an odd symbol.  I like the symbol because it symbolizes temptation.  It is symbolic of Bella's temptations regarding Edward, but an apple has also historically been used as the "forbidden fruit" that Adam and Eve ate in the Garden of Eden.  In Twilight, readers get a very good look at the symbolism involving the apple, temptation, and Edward.  Bella has recently found out that Edward is a vampire, and she isn't quite sure what to do with that knowledge.  In chapter 10, the two characters are sitting down together at lunch.  Edward grabs an apple for Bella to eat.  She picks it up and considers whether or not she will eat it. 

"Take whatever you want," he said, pushing the tray toward me. "I'm curious," I said as I picked up an apple, turning it around in my hands, "what would you do if someone dared you to eat food?"

At the same time, she is considering the possible implications of a relationship with Edward.  Should she take the forbidden fruit that is Edward or not?  Interestingly, at this point in the story, Bella puts the apple down and eats some pizza. 

I put down the apple and took a bite of the pizza, looking away, knowing he was about to start.

A second and more obvious symbol is the car that each person drives.  Each car is quite symbolic of who that character is as a person/vampire.  Edward drives a Volvo, and that manufacturer has built an empire on creating some of the safest cars around.  Edward exists to protect Bella.  It's not only Edward's car that is appropriately paired.  Emmett is a rough and rugged type of character, and he drives a rough and rugged type of vehicle.  He drives a Jeep.