There are several factors, but the two biggest are debt ratio and payment history. Your debt ratio tells the bank if the new car loan is affordable. Debt Ratio is the amount of money going out monthly to pay debts vs. the amount of money coming in each month from wages/pensions/etc. Your payment history shows the bank if you have a good track record of making your loan/credit card payments in full and on time.
After that, some other factors could be your credit score (provided by either Equifax or TransUnion), how long your borrowing history is (a couple late payments aren't a big deal if they were spread out over 10 years, vs. someone in their early 20s who already has a few late payments), how large any past debts have been (if your biggest loan was for $10,000 and now you're trying to borrow $50,000 a co-signor may be required), how long you've been at your job (often but not always a three month minimum is required), length of term (the longer the term the higher the risk for the lender), and your equity position on the new loan (do you have any money down or a trade in? Do you owe money on the trade?) are all factors that are considered.
If you have any concern at all one of our Financial Services Managers would be happy to discuss your own personal situation and advise the best path forward. We can even pull your credit bureau report and help you calculate debt ratio and even submit your application for a pre-approval.