Many people have bad credit become fixated on the idea of a particular score or number. Having a "beacon" score of 600, 650 or 550 and being able to get a car loan with the same, depends not so much on your score, per se. It depends more on the lender that you choose to obtain your credit through.
So if you are wondering if you can get a car loan with a credit score of 600, the answer lies in understanding lenders and choosing the right type of lender to submit your credit application to.
There are many different people with many different credit scores and there are also many different lenders that have very different requirements for a car loan. What this means for you is that rather than wondering if you can get a car loan with your particular credit score, you should be looking for a lender that will accept you with your particular credit score.
For example, some lenders that offer car loans prefer that the applicant have a credit score of at least 700 or better. Other lenders may look for a score of 650 or above, while there are some that will offer car credit to someone that has a score as low as 480.
Credit takes a long time to improve. It's a great idea to work on improving your credit score however, while you are working on that you can still get approved for a car loan if you simply find the best lender to suit you. You may be pleasantly surprised at what is available for you, based on your income.