Hoppoz,
You are correct, the exhaust is not a Brabus it is a stainless steel Janspeed custom one made in the UK. It makes a significant difference to the power delivery, sounds great and can look fantastic when it fits the valence properly, mine does not! The Brabus exhaust was an excellent fit but did restrict the exhaust flow a bit too much. I have Janspeed charge cooler pipes too in addition to several other induction, engine, brake and general mods.
UK