Gave the Blu of this a look when it was released as part of the Shout! Factory collection of Roger Corman films and was stunned to realize that I had never seen it before. I have no idea what film I was confusing this with from my youth, but I had somehow thought this was a cop drama, not a post apocalyptic tale involving giant armored RV type vehicles.
It's a fun watch and I particularly enjoy the on again off again indications of how fucked things are, as the weird colors in the sky come and go somewhat conveniently when they are involved in other things.
Give it a rental.