I dont have a clue how Red Bull have actually developed a car this fast, the technical spec behind it will be very interesting when it all comes out 
Simple really, something is not legal in someway, I think sooner or later somebody will work it out.
Not neccessarily. The double diffused wasnt illegal when it was introduced, it could just be a new development within the team? I do have to say the speed it seems to have looks as if there is a rabbit off somewhere.
They have flexible wings. That's what makes them so fast. There are many theories as to what is going on with the wing, how it's built, etc.
The one I think is the ACTUAL reason is the way they lay the carbon fibre layers on the wing. It's done in such way that they'll be solid straight when at low speed/being tested (I think it's only 150kg it's tested with) and when it gets enough downforce put across it, it'll flex. Remember that the wings are subjected to 450kg+ at speed, so of course it'll pass the FIA test with only 150kg. Just because it passes a test doesn't make it legal.
And I'm tired of hearing people say "ooooo Vettel is the best driver out there!". No he's not! Hamilton and Alonso are the best in F1 at the moment. Vettel JUST won the title with a FAR superior car than the rest. If Hamilton or Alonso had the same car last year they would have won the title half way through the season, the same way as Button with Brawn. He had a cracking first half of the season then when other teams brought out their double diffusers suddenly Button only won I think 1 or 2 races in the second half, but won the title because the Brawn was untouchable in the first half. The problem with Red Bull is that no one knows how they're doing the front wing business, so no other team has brought their own flexi front wing.
There was another theory that last year's RB had a flexi front nose, and that they had a discreet driver operated movable front wing (operated by the legs), but I don't believe them theories as much, I stand by the way the carbon is arranged.
