Finance car with or with out a balloon payment
That interest rate (13%) is steep, and the balloon payment will have him paying more interest longer. Investing the difference is a risky proposition because past performance of an investment is no guarantee of future performance. Is taking that risk worth netting 2%? Not for me, but you must answer that last question for yourself. To your edit: How disruptive would losing the car and/or getting negative marks on your credit be? If you can quantify that in dollars then you have your answer.
My grandmother passed away earlier this year. When I got my car 3 years ago, I did not have good enough credit to do it on my own or have her as a co-signer. We had arranged so that my grandmother was buying the car and I was co-signing.  A similar situation was happening and I went to my bank and took out a re-finance loan prior to her passing. I explained to them that my grandmother was sick and on her death bed. They never once requested a power of attorney or required her signature. I am now the sole owner of the vehicle. "Care to elaborate? It is my understanding that any asset can be rehypothecated at least in theory. By saying these car loans ""aren't"" rehypo'd, do you mean this is not the practice, or that there is a law/regulation prohibiting it?" Not sure if it is the same in the States as it is here in the UK (or possibly even depends on the lender) but if you have any amount outstanding on the loan then you wouldn't own the vehicle, the loan company would. This often offers extra protection if something goes wrong with the vehicle - a loan company talking to the manufacturer to get it resolved carries more weight than an individual. The laon company will have an army of lawyers (should it get that far) and a lot more resources to deal with anything, they may also throw in a courtesy car etc. "I think everything in your case is just simply missing one important rule of how credit works. Essentially, your MIL cannot get a loan. You can. You are making her a large loan that she cannot get for herself. That is all. That is the essence of what this deal is. It is not without interest - she makes a financial contribution toward your son, you get the deal in 2 years assuming she doesn't default (she will), etc. Imagine it this way: you are sitting in the dealership with the dealer and your MIL. She wants a loan to pay for the car. The dealership says, ""you are way not credit worthy."" So your MIL says, ""why doesn't my son-in-law take out the loan instead?"" Now the dealership says, sure, that's fine. From the dealer's standpoint, every other part of your arrangement is irrelevant - boring, even. The only magic trick is in who takes the loan out, no other difference. You're letting your MIL pull a car out of her sleeve like a magician, and in taking the deal you're believing her.  This sentence: I am pretty sure that the ex-MIL will not let me down (I've loaned her large sums of money before and she always promptly repaid).  is everything. You're making a rather large bet that the things that can go wrong in two years - including any situation involving your wife's welfare - are rather miniscule. And furthermore, that the few times she's paid you back - that did NOT convince banks and dealer she is more creditworthy - justifies her good creditworthiness. Is the interest worth it? Do you really believe that your MIL needs to wring a car out of you before she would consider contributing to her grandson's well-being (which is, essentially, the interest)? But wait, it's NOT everything. Her daughter (my ex-wife) would drive it for 2 years and then turn the car over to our son. Even if your MIL is creditworthy, the woman you described as follows: Her daughter, though, is a loose cannon. Will be holding and returning the collateral in this deal. Things she can do include: So I'm arguing two points: Obviously my opinion on this is clear. I hope I did a decent job of explaining where the components of this deal (credit, interest, collateral) play out in the eyes of a dealer or bank, and get lost in the mechanics of the rules you worked out with your family." "Yea but they might feel swindled and that you pulled a fast one on them, and not be as willing to give you good deals in the future.   Like, as a totally non mathematical example, they have a car for $50k. They lower the price to 40k with a financing that will bring total payment to 60k. Their break even on that car is let's say 45k. The financier cuts them a commission on expected profits, of maybe 7k? They made an expected 2k on the car. But if you pay it all off asap, they may lose that commission, be 5k in the hole on the sale, and pretty upset. Even more upset if they finance in house.   So when you go back to buy another car they'll say ""fuck this guy, we need to recoup past lost profits, don't go below 4K above break even.""   I'm not really 100% on how financing workings when it comes to cars but from my background in sales this is the bar I would set for a customer that made me take a loss by doing business with them if they tried to come back in the future.  This doesn't take into account how car dealerships don't own their inventory, finance all of their cars and actually ARE willing to take a loss on a car just to get it off the lot some times." The optimal down payment is 0% IF your interest rate is also 0%. As the interest rate increases, so does the likelihood of the better option being to pay for the car outright. Note that this is probably a binary choice. In other words, depending on the rate you will pay, you should either put 0% down, or 100% down. The interesting question is what formula should you use to determine which way to go? Obviously if you can invest at a higher return than the rate you pay on the car, you would still want to put 0% down. The same goes for inflation, and you can add these two numbers together. For example, if you estimate 2% inflation plus 1% guaranteed investment, then as long as the rate on your car is less than 3%, you would want to minimize the amount you put down. The key here is you must actually invest it. Other possible reasons to minimize the down payment would be if you have other loans with higher rates- then obviously use that money to pay down those loans before the car loan. All that being said, some dealers will give you cash back if you pay for the car outright. If you have this option, do the math and see where it lands. Most likely taking the cash back is going to be more attractive so you don't even have to hedge inflation at all. Tip: Make sure to negotiate the price of the car before you tell them how you are going to pay for it. (And during this process you can hint that you'll pay cash for it.) "One part of the equation that I don't think you are considering is the loss in value of the car.  What will this 30K car be worth in 84 months or even 60 months?  This is dependent upon condition, but probably in the neighborhood of $8 to $10K.   If one is comfortable with that level of financial loss, I doubt they are concerned with the investment value of 27K over the loan of 30K @.9%. I also think it sets a bad precedent.  Many, and I used to be among them, consider a car payment a necessary evil.  Once you have one, it is a difficult habit to break.  Psychologically you feel richer when you drive a paid for car.  Will that advantage of positive thinking lead to higher earnings?  Its possible. The old testament book of proverbs gives many sound words of advice.  And you probably know this but it says:  ""...the borrower is slave to the lender"".  In my own experience, I feel there is a transformation that is beyond physical to being debt free." The price inflation isn't a percentage, it's a fixed amount. If the dealer adds $R to the price of both the trade-in and the purchased car, then everyone ends up with the right amount of money in their pockets. So your formula should be: D + T + R = 0.1 * (P + R) Since this is the reasoning: I don't want to bother with micropayments, and harassing her for   monthly payments. You must do one the following: Provide the money to your mom as a loan (i.e.: with a note and interest) payable when the full repayment of the loan to the bank is done (i.e.: balloon note). The terms of the note should be that the money to be used as collateral for the secured loan from the bank. Provide the money to your mom directly. In this case you have to pay gift tax on $7K (above the 13K exemption limit). Since you want the money back - you'll probably want the option #1. Your interest rate should be above a certain level to avoid reclassifying it as a gift by the IRS (your tax adviser can help you with that). Your mom will pay interest to the bank on the secured loan, and to you on the collateral (unless you wave it, subject to gift tax, again - talk to the tax adviser). You will only need to harass your mom about the balloon payment in the end. This is not a tax or legal advice. Talk to your tax adviser and a legal counsel about the details and additional options. No, it would not show up on the income statement as it isn't income. It would show up in the cash flow statement as a result of financing activities. I agree with the deposit part. But if you are buying a new car, the loan term should meet the warranty term. Assuming you know you won't exceed the mileage limits, it's a car with only maintainence costs and the repayment cost at that point. "Convenience, and of course money. In case of an event, you'll have to spend the full worth of money to fix/replace, while if you're insured - you get the insurance to pay for it. It is up to you to decide, if the money saved on the lower premiums worth the risk of paying much more in case of an event. Of course, the cheaper the car the more it makes sense not to pay the premiums. Many people do that. Regarding the bargaining power, I actually think that you would pay less if it is not going through insurance than the bill the insurance pays. I fixed a nasty dent for like $300  at one shop, while at the other they said ""It's $1200, but what do you care, your insurance will cover it"" (I had $500 deductible, so in the end it was cheaper for me to pay $300 without the insurance at all)." "It sounds like you're basing your understanding of your options regarding financing (and even if you need a car) on what the car salesman told you.  It's important to remember that a car salesman will do anything and say anything to get you to buy a car. Saying something as simple as, ""You have a low credit score, but we can still help you."" can encourage someone who does not realize that the car salesman is not a financial advisor to make the purchase. In conclusion," "A repossessed automobile will have lost some value from sale price, but it's not valueless.  They market ""title loans"" to people without good credit on this basis so its a reasonably well understood risk pool." I'd finance the car (for 60 or 48 months), but stash enough money in a separate account so to guarantee the ability to pay it off in case of job loss. The rationales would be: Note that I'd only do this if the loan rate were very low (under 2%).