If it's the last week of the month, odds are that Alison Southwick and Robert Brokamp are going to amble over to the Motley Fool Answers mailbag to find out what it is their listeners really want to know. And for added gravitas and expertise, they've brought in reinforcements: Naima Barnes, a financial planner with Motley Fool Wealth Management, a sister company of The Motley Fool.

In this segment of the podcast, they help a self-employed woman narrow down her options for finding the best deal on a car loan. She and her husband have significantly different credit scores, incomes, and sources of income. But when it comes down to it, if she applies for the right kind of loan, only one metric will matter.

A full transcript follows the video.

This video was recorded on May 29, 2018.

Alison Southwick: Our next question comes to us from Leisha. "I'm in need of a car, soon. I am self-employed, though the vehicle will be used for personal use, not business. I'll need to take out a loan, and I see three options. One, apply by myself. Self-employed with a low net income [$22,000] but with a good FICO score of 760. Two, husband applies by himself with higher income [$79,000] but some late payments and a much lower FICO score of 690. Three, we apply jointly to show his income, too, and both of our FICOs. What kind of documentation would be needed to document my income? Is there any chance that a bank would be impressed with my FICO store and not want to see 1040s? Do we have a better shot applying for financing with a car dealership's financing or my local bank? Thanks so much."

Naima Barnes: First of all, taking a look at credit scores will play a factor when choosing a car. There are a bunch of calculators out there on like Bankrate and NerdWallet that you can use to see what you would qualify for.

And in terms of whether you should apply as a single or a joint owner, usually when you apply for a joint car loan it's when you don't think that you're going to qualify for a loan on your own. You want to steer away from that, because his score is lower. In that case, I would say apply by yourself, but go in pre-qualified.

You can go onto one of those calculators. They'll give you different rates of loans in your area and then you can pre-qualify for it and take that to the dealer and say, "I pre-qualified for this amount. Will this work?" They'll also ask for a proof of income, whether that be with your tax return or 1099. If you are filing jointly, then it will show that you guys have enough income to support the needs for the car.

Robert Brokamp: And generally speaking, the dealership is not going to give you the best rate. Obviously, that varies from dealer to dealer, but generally speaking you're going to get a better deal from a bank. And to answer one of her questions [is it possible to even get the loan based on the FICO], I was able to do that through a service called LightStream, which comes through SunTrust Banks. All they wanted to see was our credit score. We did not have to provide any other information. It was very easy to get the loan, and it was easy to pay it off, because we paid it off sooner, so that option does exist.

Barnes: When I applied for my car loan, I went online and looked at Capital One and Ally. They didn't ask for anything but my credit score, either.

Alison Southwick has no position in any of the stocks mentioned. Robert Brokamp, CFP has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.