Why isn't "There is no car, there is no job" accepted? Is that not what it means in this example?
It has to be correct. because they have used "plural form of both car and job"
In this sentence "машини" and "роботи" are in the genitive case and not in the plural form. The forms coincide. "Немає" requires genitive.
"Job" is countable: "I have two jobs."