So by now most of us have seen the various photos and videos of McLaren's new model, the 650S, and there seems to be some controversy regarding the styling. Some are underwhelmed, some are upset, and others are disappointed they didn't go further. Most of that seems to stem from folks not entirely understanding what the 650S is, believing erroneously that it is an entirely new model from the ground up, rather than what it actually is, a 12C with a few mild updates. To help everyone understand what I mean, I'll show you.
First, the front. It's a 12C with some P1-inspired touches for the headlamps, side indicators, and air intakes, but the hood, license plate area, mirrors, and cabin remain from the 12C:
Here's the P1 for reference. Notice that, essentially, just the headlamps, negative area for air intake (but not the actual air intake shapes themselves) and fenders are similar between the 650S and P1.
Onto the front corners then.
Clearly we can see that the 650S is an evolved 12C: again the hood, fender shape (except for the leading edge), mirrors, license plate area, length, shape, etc. are the same. We see that the side air intake between the door and rear wheel has been changed from the two-"blade" design on the 12C to a single one that blends more into the body line, similar to an R8 or Lamborghini, for better or worse. Compared to the P1, the previously-mentioned headlamps and bumper shape are shared, but that's mostly it. Perhaps Woking had too many headlamps left over from the P1 project that they don't expect to use in future repairs?
Let's move onto the side profile now.
Again, it's a 12C with some modifications. Again we see the side intake differences, and the reshaped headlamps, but that's about it. The 650S even shares the same cut lines and shapes for the side intakes, just one piece instead of two. Compared to the P1, the door lines and cabin shape are very nearly (or actually) the same (they use the same carbon fiber floorpan, IIRC).
And so we end at the back.
There is essentially no difference at a glance between the 650S and 12C, save the blacked-out part shared with the 12C GT Can Am Edition pictured below it. This comes as no surprise, as the 650S and 12C are mostly the same car, after all. I wish they would have put the P1's tail lamp "rope" shape on the 650S (see below), as the horizontal bars that the 12C and 650S use are rather boring, but may save cost and complexities as they're likely universally legal.
I won't bother comparing the cabins, as it's mostly just a difference of materials, and the availability of the P1's carbon fiber seats.
So, in summary, the 650S is a 12C with some front-end bits from the big brother P1, and some minor updates here and there. Were I of the means, would I get a 650S over a 12C? Perhaps, but it would be in McLaren/Papaya Orange, and it'd have to be the Spider.