Imagine Guinness issuing a directive to bar staff that after painstakingly pouring a pint of its gloopy dark stout they should lop off the head with a spoon before serving. A topless 911 Turbo has always seemed a similarly perverse idea that disrupts the integrity of a car designed for people who take their driving more seriously than their sun tan. Previous 911 Turbo Cabrios have never been bad per se – we can’t think of many soft-tops with a better blend of blistering performance, huge all-weather grip and day-to-day useability – they’re just poor 911 Turbos compromised by the extra weight of the measures needed to shore up the loss of bodyshell rigidity.

But now the approach has shifted. If there was an urgent need for the Turbo to raise its game to cover the sudden step-change in the pace and talent of the opposition, the Cabrio hasn’t been left behind this time, Porsche’s engineers having invested whatever it took to narrow the dynamic gap between Cab and coupe. If anything, the soft-top is the bigger winner, deriving an even greater benefit than the hard-top from the active engine mounts that come with the optional Sport Chrono Pack. These hydraulic mounts ‘pump up’ during hard cornering to provide stiffer location for the engine which, in the inevitably less rigid Cabrio bodyshell, is claimed to bring a crisper, more precise feel to the chassis’ behaviour that’s ‘almost as good as the coupe’s’ according to Porsche’s tame rallying legend, Walter Röhrl.

Yes, the Cabriolet weighs 75kg more (additional metal to reinforce the sills and floorplan, plus all the gubbins for the powered fabric hood) but it’s a fairly modest increase measured against the 13 per cent improvement in torsional rigidity and hardly puts a crease in the accelerative potential of the 493bhp and 479lb ft delivered by the all-new direct-injection 3.8-litre flat six, 0-62mph taking just 3.7sec, 0.2sec longer than in the coupe.

And what the Cabrio loses in inconsequential fractions to the coupe against the stopwatch, it more than gains in the enhanced subjective rush of the experience with the hood down. All right, the Cabrio doesn’t handle quite as tidily as the coupe but it’s much, much sharper than its 3.6-litre mk1 997 predecessor and probably quicker point-to-point than the previous 3.6 Turbo coupe. More refined and comfortable without a doubt. That’s real progress. So a bad idea come good? On the right road with the sun high in the sky, absolutely.