... This is one hell of a copium post lol.
Hopefully you are just misunderstanding, or rather, not understanding how it works.
It's literally a random algorithm with a max resell value of not being anywhere near the price of the car when new.
Prices of all cars so far, from what I've checked since the update was released, have been anywhere between 1/3rd of the price to about 2/3rds (30 to 60% basically, more or less).
I am not that bothered by this, in pretty much the vast majority of games the resale value of anything you sell is always below that of when you buy them. This is specially true for cars in games.
There's only one way to make a profit from this and it's pretty much irrelevant in the grand scheme of things, it's when a LCD car (and only LCD cars get this treatment) gets a huge price increase between updates.
The only cases of cars that had this happen for them are the Ferrari F40 and the Porsche 911 Strassenversion, and only the 911 is possible to sell for a profit if you had bought back when it cost 3 million (the car is now 9 million, 3x the price).
This was a very rare exception, not the rule. Any car that costs more than 12-13 million credits, you are never going to profit off of them ever, because they will reach the 20 million cap and 60% (more or less the highest resale value I've seen) of 20 million is 12 million.