The most unreasonable car in the world now also lacks a roof ? which doesn't make the new Bugatti Veyron 16.4 Grand Sport any slower than the coupe but creates a sharper, more intensive experience.

The fraction of a second it takes to plant Veyron Grand Sport roadster's accelerator is an instant that will change the way you perceive a car forever as it takes you on a trip to the very limit of physics as we know it. And now without the cockpit's cocoon, the experience is all that much more profound ? real, not least by the gurgling hiss and roar of induction centimetres behind your head?

It's enough to make you duck in avoidance before you get used to the fact it won't actually eat you alive.

And by the time you realise what's going down, the beast has ruptured the European summer air. Those four turbos now furiously compressing the breeze into eight litres of 16 hungry cylinders as Veyron howls literally into the unknown ? disposing with 100km/h in 2.7 seconds. Your entire being is thrust backward against that hand embroidered leather chair as you strain your neck to keep your chin down to focus on the road ahead.

More guided missile than car

Veyron is more guided missile than car ? the experience is more explosion than acceleration as 200km/h charges up in 7.3 seconds, the all-wheel drive still scurrying under you as Grand Sport seemingly achieves the impossible in turning 736 kilowatts into literally blinding acceleration without the histrionics of a staging dragster.

There's no real wheelspin, no tyre smoke, just plain, unadulterated warp-speed acceleration as it transforms straight stretches of road into galactic worm holes, its seven-speed Ricardo double clutch gearbox invisibly swapping cogs as you go.

Lift off and the wastegates twitter in almost eerie unison as it blows off. Brake and Grand Sport demolishes progress with a force on your cheeks even more impressive than that you were battling against under acceleration just moments before.

Acoustic avalanche

Veyron is fast, incredibly fast, but that should surprise no one. But the acoustic avalanche that accompanies that acceleration in the Grand Sport Roadster is shocking. Nothing short of "seismic" describes how that dual-V8 staccato stuns its occupants into almost disbelief: Veyron Grand Sport Roadster not only accelerates faster than most anything on planet earth, it also tells you exactly how it's doing it through that incredible open-top soundtrack.

At two tons, Veyron corners impressively effortlessly, too. Precise, humble and confidence inspiring, the open Bugatti is also well balanced, harmonious and comfortable in a rather hot hatchback kind of a way when not pressed.