Federico wrote:I think that is just a "M" setting on the knob and say "Magic" is just a method to be sure the driver didn't misheard the letter.
Setting to tighten the diff friction plates when the tyres start to go off to even out traction capability?
I think that Hamilton used this setting just before his gearbox hydraulic system blocked leaving him with no gears.
It was probably bits from the dif friction plates that were damaged when he skimmed the wall in qualy.
Choice was change the gearbox and lose grid position or risk a blockage.
Not replacing the gearbox and taking a grid place penalty was probably to ensure the move by Hamilton to Merc.
Such a diff failure was predictable after the wall incident and would almost certainly result in a DNF.