Sorry, but there is no "cut and dry" answer for your question. As a former Auto Loan Underwriter for a bank, I can tell you that every situation is different. Here's a little "inside information" you can use before going to a financial institution for your loan.

Normally, banks use "ratios" for calculating whether someone qualifies for a loan or not. Typically, the "ratios" are "28 / 36". That means 28% of your gross income is allowed for your housing cost (mortgage/rent), and 36% of your gross income is allowed for your total loan liability (ALL loans, credit cards, indebtedness - INCLUDING your housing costs - AND the loan being applied for). The rest of your income is considered necessary for living expenses, taxes, insurance(s), and personal expenses. Any loans that are written when the numbers fall outside of these ratios are called "exceptions".

"Exception Loans" are reviewed by the bank's Board (usually monthly) to see if an underwriter is in the habit of making "risky" loans. However, there are solid reasons for an underwriter to make "exception loans". Some of the reasons include "excellent credit history", an unusually high income (someone who makes $100K/year can much more afford a 40% - 45% total income to debt ratio than someone making $25K/year - they have much more "disposable income"), an unusually high down payment percentage (having a lot of money down makes the applicant less likely to let the loan go into default), and additional collateral (backing the loan with collateral value that far exceeds the amount being lent - security interest in a house or commodity).

The one thing that influences a loan application MOST is the "loan to value" ratio - how much is being financed (loan) compared to the value of the collateral (car being financed). The more money down on the "car", the lower the LTV, and the more appealing the deal is to the bank. Sometimes a great LTV can overcome a poor credit history.
GTO Judge refers to the olden days when banks gave away toasters and coffee makers to draw in clients with new accounts. Things were a bit different then. Banks are more "fee oriented" now, so a "long standing customer relationship" with a bank means much less that it used to. One thing he referred to that IS very pertinent is that you don't want to overburden yourself with a car payment. Banks look at automobiles as having decreasing value and are not considered long term investments as real property (real estate) is that normally goes up in (resale) value, so they're a bit more stingy when it comes to writing exceptions.
See my post here for more details.

Whatever you do, DON'T put yourself in a situation where you end up being a slave to your car payments. Nothing takes the pleasure out of having the car of your dreams faster than giving up everything else to own it.