There is actually one other way of seeing this which I realized. The current generation of M3 and the ex M5 (so E9X and E60 Ms) both had pretty decent sounding exhausts that were somewhat similar. The next generation is a different story, there is going to be a massive gap in sound between the new M3/M4 and M5. I loved how my piece of crap 70k M3 could sound as good as the 6 figure M5, but not anymore
