I love my 640i GC and it truly is close to a perfect car for me.
While I am OK with the power output (minus the occasional turbo lag in corners when driving more spirited), I am missing a bit of sound "drama" when driving.
I would prefer not to "gut" the car with an aftermarket exhaust system, although am open to installing M-performance exhaust since at least it can be done at the BMW dealership. Although it would be nice to have a quad tip system (can other tips be added to the M-performance exhaust).
I care only how it sounds inside and if 640i came with an Active Sound Module (like 640d), I'd code it to sound like M6 and be perfectly happy
Another route I was thinking about is to install JB+ as it seems it adds a bit of crackles and pops to the original exhaust (
). No idea how it sounds inside though.
I know sound is very subjective thing. Pretty noob here when it comes to exhausts so some direction from you resident experts would be appreciated!
(Interestingly enough, when I was deciding 650 vs 640, sound was something that I thought would be much, much better on 650, but I barely heard the difference when I test drove it.)