You'll meet a lot of NPC's along the way to the border in Road 96, and none of them are quite as endearingly funny as Mitch and Stan. In the "Wild Boys" chapter, you'll meet them by having them stop you in the middle of the road and jump in your car. Since the chapters in the game are procedurally generated depending on the choices you make and what teens you choose to play, this can happen any time in game.