McLaren certainly know how to get the orders in. For the 675LT they said they’d only make 500. They’d just about made the announcement before all 500 were sold. But the interest was there, so what could they do? Genius, make a convertible. But of course they felt they could only make 500 of them. And they’re all sold out too.

So what will those 500 owners find out when they take delivery? They’ll find that the car they bought is very like the coupe, and that’s a compliment. The 675LT coupe is obvious the solid basis of the convertible, although the one with the solid roof is 40kg lighter than the convertible thanks to the inevitable extra work on roof and support.

The LT, which stands for Long Tail, is a mighty machine in either configuration, a much more track-focused car than the 650S on which it is based. On the track it was a wild thing, but for this test we got to drive it on the road. In the rain. On speed-restricted roads. Under such circumstances, how much worse would it be than, say a Ford Focus?

The 675LT is larger and has more power than even a McLaren F1, so the trick is simply to control the devilish 666bhp on streaming roads. But it’s an easy trick. The car is pretty tractable, working steadily up through the seven-speed auto box. You certainly don’t need to push it up from Normal mode for this sort of drive, as you’ll get immense acceleration simply by looking at the throttle. But the engine likes to rev, and produces max power at 7100rpm, so you can simply keep the revs down and keep control, and only occasionally fire it up the rev band, accompanied by the yowling tone of the titanium exhaust.

When you pull the pin on this thing, you realise just how much horsepower there is, but the clever traction control systems let the rear tyres light up and then brings the whole thing back on to an even keel without any undue drama.

As you leave the drive mode in Normal, so that too keeps the suspension about as compliant as it’s going to be. For what it is, this is a pretty comfortable ride, with only the occasional pothole crashing through. Add to this absolutely sublime hydraulic steering with immense finesse and feeling, and you feel in control, plugged in, wired up, every moment of your journey.

In the cabin the sports seats are pretty comfortable for this sort of car, certainly capable of keeping you comfy for hours at a time. There’s some noise intruding from road and wind and, of course, from that rasping exhaust, which you can make pop and bang by shifting modes if you want to.

So the main difference is the roof, and that’s not intrusive. It’s got electric operation and, if you want to hear yet more of that glorious 4.0-litre V8, then you can lower the rear window on its own. You get spine-tingling noise coming in, but it isn’t accompanied by rain or cold air, which is clever and welcome. On this day we kept the roof up and it was hardly different to the coupe.

We know this 675LT is utterly awesome on the track, but what came as a pleasant surprise was how good it felt on the road in conditions that were about as polar opposite to ideal conditions as you could get. This is a superbly engineered car that can wow on the track and then drive you home in some comfort and confidence, even if home is a long way away. The Long Tail is going to cast a long shadow on high-end motoring for a while yet. Even if they can’t think of another variant to justify another 500.

McLaren 675LT Spider

Location: Scotland

On sale: Now

Price: £285,450

Engine: V8, 3799cc, twin-turbo petrol

Power: 666bhp at 7100rpm

Torque: 516lb ft at 5500-6500rpm

Gearbox: seven-speed dual-clutch automatic

Kerb weight: 1360kg

Top speed: 203mph

0-62mph: 2.9sec

Economy: 24.2mpg

CO2/tax band: 275g/km / 37%