The McLaren MP4-12C is an amazing vehicle. It was designed to be just a little bit better than the Ferrari 458 Italia in every metric, and it succeeded. Some may prefer the Ferrari subjectively, but the Macca is objectively faster. More still, every year McLaren has updated the car, making it even better, and offered the upgrades to existing MP4-12C owners free of charge. Yup, a 2011 McLaren can be taken into a dealership and upgraded to 2013 spec at no charge.
This year, the car's engine is up for an upgrade, since 616 horsepower apparently just wasn't enough. We know that the gasoline powered element of the P1's hybrid powertrain is a tuned version of the MP4's engine, and that it makes a whopping 727 horsepower, but we'd also be very surprised if McLaren took it that far. Our money is on the 650 to 680 hp range, which will still be absolutely incredible, and would likely be enough to drop the car's 0-60 time below the three second mark.