No matter what BMW does with Mini, it’s an instant success – at least that’s the message from executives confident they have one of the greatest and most envied brands in the automotive industry.

Basic petrol, Cooper, Works, diesel, accessories – all have been embraced by an eager audience.

And there’s little doubt the same will be true for the new convertible, especially in the UK where buyers have a national obsession with soft-tops (last year they accounted for 3.8% of the new car market). The 12-month order book was expected to be full by the June 26 launch date: that’s 8,000 models each with a named customer. Cue more waiting, full list prices and sector-busting residual values.

These people have not yet driven the car, but they know they want one. Why? Because it’s a Mini. Whether the brand can retain that magic as BMW squeezes out estates and van versions is open to question, but for the moment dealers are happy to invest in new outlets safe in the knowledge that they will get instant payback.

So what’s the new car like? Cosmetic changes include new lower front bumper with single chrome strip and redesigned rear light unit. Inside are more storage areas, improved seat support, refreshed instrument panel and new three-part fasia.

Thickened inner/outer sills, cross-member strengthening and heavier gauge sheet metal around the now absent B-pillars combined with the soft-top mechanism add 100kg to the weight of the car. It feels it: the sparkiness of the basic 1.6-litre engine in the hatch is lost, while even the Cooper feels sluggish, despite its paper 0-62mph sprint of 9.8s (0.6s slower than the hard-top).

But that strengthening is necessary. Not only should the Mini achieve a high Euro NCAP score, scuttle-shake and body flexing is well within acceptable levels, particularly when compared to rivals.

The roof is a two-stage operation. Hit the button and it slides back 40cm to create an open sunroof; press again and the roof folds snugly behind the rear seats. The process takes just 15 seconds. The downside is the thin front section of the roof, which means a fair amount of wind noise at speed with the top up.

When it comes to customers, Mini says retailers can throw away the market research rulebook. The demographics include everyone, aged 17 to 90. According to the company the convertible is about mindset, not social grouping.

Strengths:Style, design, pricing, two-stage roof
Weaknesses: Sluggish, bit of scuttle-shake, wind noise
Opportunity: Exploit demand for convertibles
Threat: Waiting times
The USP: It’s a Mini. Without a roof
Prices: One £13,325; Cooper £14,625; S £17,595
Engine: 1.6-litre petrol
Transmission: 5spd man, fwd
Performance: 0-62mph 11.8/9.8/7.4c; speed 109/120/134mph
Efficiency: 39.2/39.7/32.1mpg comb 173/175/211g/km CO2
CAP RV (3yr/30k): One: 59%, £7,700; Cooper: 58%, £8,325; S: 55%, £9,525
Rivals: VW Beetle convertible, 206 CC, Megane CC,