B-movie? Try D. This flick is cheap, lower than low budget with serious issues with scenography (brand new trucks against supposedly post- apoc buildings), costumography (neatly trimmed, fresh looking actors in supposedly post-apoc world).
However, despite bad acting the movie has some good points. No CGI, all is done with cool MadMax-esque vehicles. Attempt at Aussie accents is also sort of a bonus (for being an homage) if not a slight comic relief.
The best in this movie is the story. It doesn't have a beginning. Audience is waking up into a nightmare (just as main character does). It doesn't have an ending either. What kind of ending is there after the end of the world? In between the moment lights come in and lights come out, we see an authentic, believable story about survivors. they have hopes, doubts, they have issues, they love beyond death, they are just trying to do their best to survive. I the end, they are defeated. Again, by love...