If a personal vehicle is truly necessary to do the job—for instance, if the open position is for a courier and you don’t provide a company vehicle—then yes, asking whether the applicant has access to a car would be appropriate. However, if your concern is the employee’s ability to get to work every day in a timely fashion, it would be better to ask if they have reliable transportation while emphasizing the importance of being on time.
Asking about an applicant’s assets (like a car), or anything else that might be classified as financial information, can run afoul of equal employment regulations if the information isn’t gathered and used carefully, and only as needed. Because of this, we recommend not asking applicants if they own a vehicle (or house, or boat, or spaceship) unless it’s genuinely necessary to perform the job you’re hiring for.
This Q&A does not constitute legal advice and does not address state or local law.