In the US, Fiat aka Jeep/Ram/Dodge/Chrysler/Alfa/Fiat (in descending sales numbers) have similar depreciation to Mercedes. Mercedes/BMW/Audi all have high depreciation here because they focus on the high end leasing market. I paid literally half the original sticker price on my BMW 328i. It was 3 years old, with only 7000 miles. If you want high resale value in the US, the top brands are Subaru and Toyota. That's why I bought my Sienna new.
This illustrates something important. Everyone's situation is different. If you are going to provide information that is accurate and useful, you have to be willing to understand your audience's context.
Fiat in this part of the world is a piece of crap and has no value at all. I am talking about cars that are the Fiat brand.
Mercedes has extremely high resale value even after years and years of use in this part of the world compared with Fiat.
We aren't talking about the US, the OP is in the Europe/Middle East area.