Exit Speed (2008) on Netflix

On Christmas Eve, ten strangers board a bus traveling across Texas. Far out in the wilds they collide with a meth-addicted biker. Forced off the road by other members of the gang, the passengers take refuge in the hell hole of an abandoned scrap yard. They use improvised weapons and sheer guts to mount a defense against the murderous bikers but, as their numbers dwindle, they realize that their survival depends on doing the unthinkable. They must go on the offensive.