The Passenger Seat by Vijay Khurana

Seeking release from their small-town existence, two teenagers drive north on a vaguely plotted road trip. Adam and Teddy hope to leave boyhood behind. But they carry with them all the upsets and resentments they have accrued in their unhappy lives to date. As the pair's journey progresses, the mood fluctuates as each of them sets out to prove himself. The dynamics of their friendship begin to unravel, culminating in an act of devastating - and all too familiar - violence.