Someone fact check me here, but isn't the M Performance Exhaust for the 2 series a titanium axle back?
https://youtube.com/watch?v=sGUqhbG9ajo
I recall reading something about akrapovic co-designing the MPE thought that might have been more oriented for the M cars.
If you're state side this is on discount with free shipping at
GetBMWParts for about 1.8K. Dealership is probably gonna just charge you the full 2.2k. Labor is around 5-6 hundred iirc. Still pretty pricey to be honest.
I'm having an MPE thrown on myself. There are probably better performance mods you could do to the car first, but if you're looking for sound it seems the MPE mostly accentuates mid-range sounds imo.