The V8 motor is roused into action by twisting an ignition knob on the centre console to the right, depressing the clutch and then pressing the start button atop the chunky piston-shaped gearlever while simultaneously giving the gas pedal a generous prod or two. The 7.0-litre motor erupts into life with a raucous bark, but it immediately settles into a civilised idle.
You'll find that the clutch doesn’t call for Schwarzenegger-esque quadriceps, but slotting the six-speed Ricardo gearbox into first gear (or any other ratio) requires a firm hand. Zenvo technical guru Troels Vollersten explains the gearshift linkages are a bit worn on the prototype car, and that a new set would make for far easier shifting.
The ST1 has three engine modes – normal, sport and race – liberating 650bhp, 850bhp and 1104bhp respectively, and selection of any of these is a mere twist-knob away. Traction control is fully operational in the normal mode, and partially so in sport… but you’re on your own in the full-power race mode.
The seat of my pants tells me even the 650bhp setting will be enough to see off most rivals, provided you’re deft enough with your clutch and gearchange work. This is no Honda S2000-style rifle-bolt gearchange requiring mere flicks of the wrist. Instead you need to manhandle the alloy knob from one ratio to the next as shifts are neither light nor quick (but perhaps the new linkages alluded to earlier would help).
Fortunately, the engine’s power delivery is relatively smooth and progressive – there’s no alarming peaks or troughs – but the blown V8 doesn’t particularly enjoying lugging at low speeds in high gear. This, plus the stubbornness of the manual gearbox, suggests the six-speed paddle-shift sequential – made by Xtrac – will be the better choice for most.
In no-holds-barred 1104bhp mode the ST1 is virtually as quick as anything I’ve ever driven – Bugatti Veyron included. However, where the Bugatti cossets you and insulates you from much of the violence taking place in the engine room, the Zenvo assaults you with an aural and physical battering.
Unleashing the full quota of power is partially achieved by opening up flaps in the exhaust, which means noise levels instantly escalate to conversation-killing levels, and full-throttle gearshifts are accompanied by a slight twitch from the chassis as 1055lb ft of twisting force does its best to unstick the steamroller rear tyres from the bitumen.
The Zenvo's brakes are massive Brembos (380mm at the front and 355mm at the rear), but given that I’m being intensely scrutinised by Vollersten, who’s riding shotgun, I resist the urge to stomp all over them.
Ride quality is somewhere between firm and rock-hard, but the production car will have a choice of three settings – comfort, normal and sport. Vollersten says shock-absorber specialist Öhlins could provide up to 30 settings for their dampers, but this would be just too much choice for most owners.
The key question: is the Zenvo special enough to warrant its exorbitant price tag? To be honest, I can’t quite see £750,000 - the quoted figure at the time - worth of value in the car, but perhaps the lure of being one of only 15 people to own an ST1 will be the clincher for some. Those that miss the boat will have to hold out for the ST2.