"It felt so good to break her in, to see how fast the car goes. Twilight vampires are very unique -- they're not like all vampires," Stewart explained at Comic-Con 2012 in July. "But I think everything about her is amplified. Everyone's powers are informed by how they were as a human . . . You want something for so long, and then they give it to you. They made me wait for it. It's like waiting for Christmas."