There's Some Good Reasons For It

Why Do Europeans Remove the Badges From Their Luxury Cars?

What I have discovered is that there are two reasons. At the bottom level, Europeans remove the badges because they don’t want people to know that they went for some base-level crapbox instead of a real powertrain. In this sense, Europeans are far more vain than us Americans: they pull off the 316i badge on the desperate hope that someone behind them in traffic believes they bought a 318i instead. 

But it isn’t only the bottom-level people who do it. S-Classes in Europe are de-badged. AMG cars. BMW M3s and M4s. When I worked for Porsche and traveled to Germany, I had this conversation with dozens of my colleagues many times, and they all said the same thing, namely that you pull off the badges on low-end cars and on high-end cars for the exact same reason: you don’t want people to know what you got.

And so, the result is that basically everyone in Europe de-badges their luxury vehicles. If you’re poor, you don’t want people to know you’re poor, and if you’re rich, you don’t want people to know you’re rich. 

(Jalopnik.com)