The problem is how to turn car-value into cash. You have a car worth $10003 and your current needs can be filled by converting $3 per hour.
chii is suggesting you sell the car. That converts the entire car at once. Then you don't have to spend any hours! As an optimization on top of that, they suggest you store the value in a bond, and pull $3 per hour out of the bond instead.
The real problem with this idea is that selling the car leaves you with no car.
Your objection that "you need the cash now" is based on a misunderstanding of chii's idea. chii's idea does get you all the cash now. It gets you the cash far far faster than $3 per hour. It gets you the cash so fast that you could actually invest almost all of it and pull out $3 per hour and do things you actually want to do during those hours.
It's not "buy a bond, have no money today, have more money tomorrow".
It's "buy a bond, drain the bond for $3 an hour today, have more money tomorrow".
Compared to having 10k under your mattress, the bond has no downside.
What do you need a car for? If it's just to go shopping, consider paying for delivery services instead of being the delivery service. If it's to get to a day job, compare car ownership to mass transit or bike committing. All of these cases can be estimated fairly easily (IRS allows deducting ~$0.50/mile, which is a good first estimate for total cost of ownership per mile).
Unless a car is a certain model, it's a liability instead of an asset, so it should be treated like any other expense. If you only use the car for local trips and commuting and taking the bus/biking is doable (perhaps less convenient), then buying a cheap car, keeping a few weeks of food on hand, and taking the bus to work whenever the car breaks down is likely way cheaper than buying a newer, more reliable car.
I used to have two cars (married with kids, so one car for each parent), and then decided to start biking to work to improve my health. I noticed that I can bike most days, and the insurance alone was enough to convince me to deal with the occasional inconveniences (e.g. when it snows, I bike to the bus stop).
The problem is that most people don't actually do the math and just assume that owning a car is better, when it's not most of the time.
