M6 vs. M3
Ok. I'm one of few who've owned both so hopefully I have something to say.
STYLING-WISE ONLY: I like the front light assembly of my 3s better than the 6s. The 6 was nice, but the 3's look like something on a spaceship, like I might open up a laser barrage on someone in front of me. I had the original grill on the 6, but the slats-stye on the 3 is easier to take care of and keep wax off of. But I think the coverings on the lights for the 6 were tougher; the actual material they were made out of was more robust and didn't chip so readily.
The rear, I think the 6 is better without the spoiler, but the 3 is better WITH it. But it looks like the actual viewing area out the back of the 3 is just right, but a spolier may cut it down too much. And the spoiler for the 6 is too big.
The 6 has those 2 rear exhausts-- cool-LOOKING, anyway, if if they're fake-ish. The single chrome one on the 3 is good, but not as ferocious as 2.
The Trunk design on the 6 is better. The 3 has an odd joint that gets snow and junk in the top, which can fall down into the trunk itself, no good in the winter. And the 3 has no good place to grab or let down the trunk, and the design doesn't let you get things in as well as on a 6.
ALso, I like the side repeater lights on the 3. They need to be clearer for during the day, but at night they can let people next to you know when you're switching lanes, and eliminate guessing on the parts of others. when you're making a turn on a dark road and someone's in your blind spot.
ALso, the side mrrors on the 3 fold back. Not usually important, but when it is ... BUt the 1st 6s had no antenna; much more classy and preferable.
And the color of the 3 is visible on the interior door frames as you're sitting in it; pretty cool.