" The new McLaren 650S is essentially the same thing as an MP4-12C. What is the difference? New headlights inspired from the P1 (which actually look somewhat tacked on) and new engine software increasing output of the 3.8 liter M838T twin turbo motor to 650 PS (641 HP).
There also are additional aerodynamic changes and minor changes to the interior. What this means is the MP4-12C prices should get pushed down as the wealthy scramble to have the newest and best. An MP4-12C for under $200k should be a realistic proposition for used 2012 models making the car an attractive performance option on the used market versus a new 650S which is expected to be around ~$300k.
Additionally, retrofitting the new engine software to the existing MP4-12C's is likely going to become very popular considering McLaren is claiming 139 mile per hour trap speeds for the 650S. That is roughly 5 miles per hour faster than the MP4-12C with its 616 horsepower.