I'm pretty sure a 7.62x39 would have no trouble defeating the Cybertruck bodywork. Their demo of how bullet proof the car was used .45 ACP, a big, soft, sub-sonic pistol round. It hits hard, but doesn't punch through material the way a faster round would.
And if the 7.62x39 doesn't do it, someone can break out the .30-06 (7.62x63 mm) "Turning Cover in to Concealment since 1906".