The siblings' hands dance together on the gearstick, their fingers entwining, igniting a spark that has nothing to do with driving. Her breath hitches as she feels his growing bulge, her own panties dampening. He watches her, eyes hooded, as she bites her lip, trying to focus on the road. The car's engine purrs, a symphony to their mounting desire. They're a car crash waiting to happen, their bodies aching for a collision. As they pull into a secluded spot, she turns to him, her eyes filled with a hunger that mirrors his. "Let's take this for a spin," she whispers, her voice barely audible over the idling engine.