Using the existing twin-turbo V12 engine that the Mercedes-Benz S600 comes with, Speedriven attack it with a number of spanners, adding water-air-intercoolers, high-flow air induction kits and a revised engine computer. This leaves the luxury limousine with a whopping 1138Nm of torque. On top of this tree-stump-pulling grunt there's also 518kW of power on offer.
This means you'll soon be driving the quickest S600 around. Speedriven also fiddle with the gearbox so it can not only handle the extra oomph but also provide more direct and more rapid cog changes. The great thing is, the gearbox setting is only engaged when the 'sport' button is pushed. So in 'normal' driving, gear changes are still soft, smooth and velvety like the rest of the car.
Decking out an S600 in this way creates the ultimate sleeper, the ultimate wolf in sheep's clothing. Acceleration times have not been specified by Speedriven but we'd expect 100km/h to come up in under four seconds dead - considering the standard, 380kW/830Nm car manages it in 4.6 seconds.
All this can be had for $US8800 ($8840), excluding installation costs. Just some spare change, then.