Dude, a brand new Hyundai Ioniq 5 starts at $42k. The used Mercedes doesn’t cost -$8. Also, if you’re in a country that uses Euros, that explains a lot. Your part costs are much cheaper for those German cars than ours are. If I lived in Europe my opinion would likely be different on German cars. Here in the US, if you used Lexus as an example, it would be a much easier argument for you to make.
I’m not even trying to say that a new car is more financially sound. That’s a silly stance to take. But a 10 year old car just isn’t going to have the same safety standards and tech of a new car.
It’s one of those things that sounds cool and fun, then you realize it’s mostly just paper work and reading logs.