Car ownership, or lack there of, is not a protected category, unlike, say, race, sex, or religion. Employers are free to hire or fire their employees for any other reason, or none at all, unless there's a contractual agreement not to, as in the case of a union collective bargaining agreement. They can decide they don't care to employee people who don't drive, they can decide the dont' care to employ people who like the Green Bay Packers, or just about anything else.