p 203, under Ram!

If the vehicle moved twice its Tactical Speed, it gains an extra 1d10 Damage for every 10 additional metres moved.

What if I move 1.5x my tactical spped? Like a venon comes ramming me for some reason and fly 33 meters before ramming me.

Tac Speed is 21 meters, so 1d10+front armour. Twice Tac Speed is 42 meters, but the Dark Eldar moved 33 meters; so would it be 1d10+front armour, or 1d10+extra d10 for the extra 10m +front armour.

It should be written

The vehicle can move up to twice its Tactical Speed; it gains an extra 1d10 Damage for every 10 additional metres moved.