The well-heeled drive the premium brands, but what of those who are a notch higher? The people who have a price on their heads - in a manner of speaking? To protect them on the move, several high-end car makers offer armoured editions of their regular cars. Audi's sole offering is the top-of-the-line A8L (long wheelbase sedan) with either a massively torquey 4.2 litre diesel or 6.3 litre W12 powered by 500 horses. It can hold off explosions, bullets and yes grenade attacks too. And its studded with technology. We review it for you.