Seems weird to me that no bank would be willing to lend. If the market value is well-documented - that is, if the bank has confidence that they can repossess/sell the car and recover their money if you default - I can’t imagine why they wouldn’t.
You don’t say what your 401K money was invested in. But suppose it was in an S&P500 index fund. What would have happened if you had left that $10K in there? I went to Morningstar to find out. I picked 1/1/2010 as a start date, and 1/1/2016 as an end date. Your $10,000 would have grown to about $20,500, a gain of about $10,500 (and an annualized return of 12.7%). Instead, you took the money out, bought-and-sold a car, and realized a gain of $10,000. So it looks like a wash. But if you could have found a way to borrow money at an interest rate of less than 12.7%, you could have done even better - especially since you would have been paying the loan back over that period, meaning your time-averaged debt (and interest accrual) would have been less than simply borrowing the full amount for the entire period.
In 2010, the NSX was a future classic, not an extant one. Values were basically the same as for any other 17-year-old luxury car: that is to say, minimal. It’s only in the last three or four years that it’s begun to appreciate - though it is now doing so significantly and depending on condition that car might now be worth over $100K. This one in unusually good condition (but with meaningful mileage) is selling for $70,000.
Most car financing entities won’t provide loans on older vehicles, but there are plenty of specialist collectible car financiers who will. Some banks (generally regional ones) will provide financing for older vehicles. Banks will also offer unsecured loans, though I don’t know if any of them will give a regular Joe a $10K unsecured loan regardless of credit history.
I think a point is missed here. Most 401k’s are not entirely in stocks. For many, a portion is in bonds and cash, to balance exposure to market. If the loan replaces bond or cash holdings, the risk does not go up ( presumably to yourself, you are a zero risk investment*) so the return actually goes up ( from 0 in cash or 1.x% in bonds to whatever you charge yourself)
If your 401k is all stock then borrowing against it is a bad idea given that most likely stock returns over the life of a car loan outpace typical borrowing rates.
*you are zero risk to you, because even if you are a poor credit risk, the net effect of defaulting on a bank loan or the consequences of being categorized an early withdrawal are about the same, or possibly slightly better if doing the 401k thing. So the borrowing from 401k does not increase your risk exposure over borrowing elsewhere.
Mine wasn’t nearly that nice, it had 70,000 miles on it. Selling it was an odd experience. The number of potential NSX buyers was small, so all the responses to my ad were from out of state. I would use my iPad and FaceTime to let them see and hear the car. If they were still interested, they’d have to fly to Phoenix and I’d pick them up at the airport using the car. This made a good impression at the curb, because it was kinda loud, visually and aurally. They would drive it around for a while and I’d show them every scratch and ding. If they liked it, they would make an offer below the asking price, which is wise. But unlike all the other cars I’ve sold, I would respond with, “no, the price is firm, I won’t come down a cent. If it doesn’t sell this month, my price will go up, because these are appreciating.” I raised the price twice before it sold.
Funny; it was the most expensive car I’ve ever bought, but the cost of ownership made it the cheapest car I’ve ever bought.
