Lenders have a duty of care to ensure you have the capacity to afford to repay a loan. If you are provided a loan and you fall in to financial difficulty as a direct result of it, lenders can be held responsible. So rest assured, any reputable lender will do the relevant checks to ensure you can make the repayments.
WARNING: If you read this website, your chances of getting car finance with bad credit will dramatically improve.
One of the major factors that a lender will look at to determine this is your income.
If you earn less than what is considered to be enough to cover typical monthly living expenses then you can be declined for credit even if you have a perfect credit rating. Having children will add to the living expenses and any other dependants you have living in your care under the age of 18. As well as other luxury costs like Foxtel, private health cover.
Even those people who earn a lot of money may be declined for credit as their expenses might be too high. So often people buy an investment property which doesn't make money and when it becomes untenanted it can cause even those with big incomes to start missing payments.
If you are a university student working part time, you may consider asking the lender to let you put Mum or Dad as a guarantor (subject to Mum or Dad approving). This will help your chances of being successful in applying for a car loan.
Lenders will ensure you do not borrow more than you can afford. You also want to make sure you can comfortably afford to repay the loan as well as being able to save at least $200 a month for a rainy day.