Hello M6 folks, wanted to do a quick intro. I am new to the 6-series forum but not at Bimmerpost. I've had multiple BMWs over the years, but recently wavered to AMG territory with the 2018 C63S. Great car, brutal acceleration, but I just could not get the 'feels' from it that my M4 gave me (my childhood dream car being the E30 M3 may have had something to do with that) ...
Anyway, long story short, found a decent 2015 M6 GC Sapphire Black / Black (30k miles for around 54k, well taken care of) that I liked and swapped it out with my C63S. I probably paid a few grands more than I should have, but dealers are spoiled in Seattle, everything tends to be more expensive.
So far, few observations against the C63S (even though these cars are from different classes):
- Throttle mapping on the C63S is brutal. The M6 is incredibly fast too, but I have noticed that I need to stomp on the throttle a bit more to let the car rev a bit
- The interior on the C63S was class. While I never liked their design language, I appreciated it a lot. I prefer simple design of the BMWs, but the M4 just felt cheap. The M6 is another story. I love the interior, even though the car is fairly old now, I think I still prefer it over the C63S - so much quality, and simplicity.
- Sound (audio) is important to me, so including that one here as well. The standard Burmester was very crisp, I think better than the HK upgrade on the M4. However, the B&O on this thing makes it sound like Skull Candy. Needed a couple hours of calibration with a sound meter, but wow!
- Exhaust noise - AMG. No question. Let's just leave it there before I start missing it.
- Handling. M6 is obviously much larger. But it somehow feels as small as the AMG to me from the driver's seat. It drives like a much smaller car than it actually is, accelerates like one, and I think the tighter cabin also contributes to that feeling. But every time I try to park my car, or look at it after I've parked, is when I realize just how long and wide this thing is. But I am okay with that ... all cars have grown bigger, that's just the trend right now ... big, practical, super saloon type muscle cars. It will eventually come around when that idea is saturated, just like how the M2 is doing it.
- Mileage. Holy crap. I've been getting 10-11 mpg mixed.
(To be fair, this car has seen nothing for bumper to bumper traffic since I got it a couple days ago ... so hoping that this will go a bit up once I get to hit some clear roads) AMG was doing around 18-19, so I thought it would be comparable. Gas bill is going to suck. 
- Lastly, looks. M6, hands down. C63S looks nice from the front, but the rear is just, meh. The widening on the AMG is also not done very tastefully, and looks like an afterthought, like a wide-body kit. The M6 to me is arguably the best looking BMW, if not one of the best looking cars in its class. The dead-on side profile is probably its weakest angle as it looks a bit too long. But other than that, the front and the rear are just perfect. I don't know if the coupe makes it look better from the sides ... It is amazing how good design holds up for so long! I do like the LCI headlights better. But they were asking mid 80s for a 17 M6, not worth the price premium IMO.
That's all for now. I am sure you have seen this a lot by now, but thought I would share what I thought coming from an M4 -> C63S -> M6.
I am going to daily this car, around 30-40 miles per day, 4-5 times a week. Any tips and how to keep this thing in top shape would be recommended (I have extended the comprehensive warranty to 75k miles, so no worries there). Or any design flaws that I should take extra care for?
I have also already ordered some black-out parts from IND (grill and badges). In the short term, also thinking of adding:
- CF or a painted splitter + diffuser (question about this below)
- Updated display unit (either just the screen, or an upgraded car play system depending on whether any of it voids my warranty)
Re: the CF parts, obviously, popular brands are running in the 1000s, but I saw a few that were reasonably priced (on ebay and EB motors).
http://www.ebmotor.com/mobile/series-c-39_185.html
https://www.ebay.com/itm/For-BMW-F06...70f6%7Ciid%3A1
Has anyone had any experience with these? Also, how hard are these to install?
Thanks!
EDIT [Add pictures]
