

They are recorded in multiple different events (repairs at a professional service, oil change, inspections, etc.), but as a buyer you would have to become active, ask for and check the papers, contact past owners, inspect the car, etc.
Because changing the odometer is easy and cheap, and can raise the price at an average of 3000€ per car, it is done rather often and not discovered in many cases.
While there are laws against it, the implementation of more manipulation resistant odometers by the car vendors is still not there yet broadly.
Source: https://www.adac.de/rund-ums-fahrzeug/auto-kaufen-verkaufen/gebrauchtwagenkauf/tacho-manipulation/
To someone that can upgrade a Nintendo switch to have 8GB of RAM, can install RPCS3 and play PS3 games on it, I would say: “Do whatever you want, you are a god amongst us. I am the peasant that lives the easy life with a SteamDeck”