system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why vehicles depreciate in value so quickly as soon as you leave the lot?
gpt
Imagine if somebody just bought a new computer and within a few days tried to pawn it off on you. Would you take this as a generous offer, or would you assume there's something wrong with it? 

Cars might be made in factories, but there are a number of moving parts that can go wrong, or worse, it could be a lemon. Within those first moments of going off the lot, you can only have things go wrong. If you want to resell it, why? You obviously aren't going to get the same price you bought it for, so you aren't trying to flip it for profit. Statistically speaking, there is something wrong with that car. 

Now lets say you waited a year. The new models of cars have come out and there could be dozens of reason one wants to sell last years car. Even if it was a lemon, the resale value is much higher than it was right off the lot if only because it's more reasonable for somebody to get rid of such a "fine" products. Unless the model in question had several recalls and/or a particularly bad reputation, you can expect a higher resale value than you would get had you sold it right out of the lot.

One last thing of note is, practically everything about selling cars is a headache of many people in the know selling to a customer they hope is ignorant. Sales people will try to mark up everything where they can, well past the actual value of the car, and sometimes up-sell things that are assumed standard in a resell market as "features" to wriggle even more money from customers. It is fairly rare that cars are actually sold at their proper value as even people who are good at negotiating a fair price get fatigued by tenacious sales practices. One of the reasons cars depreciate so quickly, is because they were never actually as valuable as the price they were bought for.