Anyone else notice the temperature is different in both screenshots, yet its the same screenshot?? 
I've never heard of a Spitfire of any kind being able to dive 12K without ripping the wings off, or being torn into tiny pieces.
Try this sometime Latrobe... Climb to 20K in a Spixteen, cut your throttle, go into a steep dive, apply full right aileron and full left rudder (called a slip)... then go get a beer from the fridge... It will take some time to get down to the deck!