Most car dealerships will require you to show and have some proof of income and a job when applying for a car loan.
But if you're unemployed and don't have any proof of income it may still be possible to get approved for an auto loan but you'll most likely be required to pay a larger down payment on the car which is usually a down payment of 30% or more and you may be required to have a cosigner sign the car loan agreement along with you to get the car loan approved.
Having no proof of income and no job can make it hard to get a car loan but it can be done if you shop around auto dealerships.
Most likely you'll also have to go to a used car dealership and get a used car instead of a new car when you have no job and no proof of income.
If one car dealership or auto lender says no to the auto loan without proof of income just shop around until you do find one that will work with you and approve your auto loan with no proof of income or job.
They're out there you just have to shop around.