The styling looks great 20 years on, being superbly proportioned, simple and elegant

LAKE COMO on a sunny day is a beautiful place. But when the rain is whipping the surface of the lake into an angry spray, and brooding storm clouds are colluding with the mountains to create a claustrophobic pocket of darkness, it’s about as appealing as Skegness in winter.

Even Manfred Grunert, BMW Germany’s ever-cheery PR, seems to have had his enthusiasm dampened by the weather. We’re here to spend a couple of days driving BMW roadsters after the Villa d’Este Concours, and this relentless gloom is not in BMW’s immaculately planned itinerary. God is clearly not a German.

Unlike most of the assembled hacks, I’m not too fazed by the weather, however. Partly because this is just another summer’s day by British standards, but mainly because I was lucky enough to drive the assembled cars – pre-war 315, 319, 328, and post-war 507, Z1, Z3, Z4 and Z8 – three years ago at the same venue. We featured them in Octane issue 40. This time I want to revisit just one. Not the 328 and 507 supercars, but the less obvious Z1: a car that was hugely expensive at launch, has always been pretty dear as a secondhand buy, and is all but forgotten today.

We didn’t get many Z1s in Britain in their short production span, 1988-’91. BMW only made 8000 and of those just 86 came to the UK. They were left-hand drive only, which didn’t help, but it was the Z1’s staggering list price – around £40,000 in 1988 – that made it a very expensive toy indeed.

And ‘toy’ is not an inappropriate word, because the Z1’s party piece is doors that drop down into its deep sills. From the outside, you press a chromed button and they lower swiftly and silently, pulled by an electrically-powered belt drive; on the inside, you give the interior handles a good tug to do the same job. Windows drop automatically into the doors, or you can raise and lower them using conventional switches.

If you want, you can drive the car with doors lowered, Mini Moke style, although the resultant wind buffeting turns it into what Car magazine described as ‘the world’s first cross-flow convertible’. The drop-down doors aren’t as much of an advantage as you’d think in tight parking spaces, however, because getting over those high sills and into a compact cabin means your legs are almost certainly going to end up flailing wildly outside the car at some point. Not cool.

Inside the Z1, you start to see where the money went. It’s finished to a much higher standard than the mass-market Z3, with leather-covered dashtop and black-bezelled VDO instruments. There’s a very designerly three-spoke wheel, while the seats are clamshell buckets with backrests painted to match the exterior. There’s not a lot of space, however – those high sills again – and the truncated boot has less room than the overhead locker in an airliner. I know, because my carry-on bag fitted comfortably into one on the plane to Italy. It doesn’t in the boot of the Z1…

So, the Z1’s expensive and it’s not terribly practical. It’s not fast, either, despite having the 170bhp straight six from the 325i. Period sources quote a 0-62mph time of either 7.9 or 9.0 seconds, but it feels more like the latter. We’ve become accustomed to modern roadsters being heavy but the Z1 was ahead of the game in 1989, weighing 1460kg when a Mazda MX-5, say, was just 940kg. That’s despite, or more accurately because of, the Z1’s outer panels being entirely plastic. OK, very sophisticated plastic – and of different types, to match the varying impact resistance requirements of different panels – but still, basically, plastic.

Expensive, impractical, not fast, but undeniably clever. The Z1 was built on a galvanised steel frame, with the outer panels bolted on. In the early days, BMW glibly suggested that you could remove or refit all the panels in 30-40 minutes and keep a spare set in your garage for when you fancied a quick change of colour. (Owners suggest the job in fact takes days rather than minutes.) A roll-over bar is integrated into the windscreen frame and the rear transverse silencer box is shaped like an aerofoil to push the back end down on the road at speed. That is very clever indeed.

And being clever was the reason for the Z1’s very existence, for it was first unveiled at the 1987 Frankfurt Show as a ‘research vehicle’ from BMW’s recently formed Technik division, under the leadership of Dr Ulrich Bez, the Z in Z1 standing for Zukunft, or ‘future’. It’s said that the Technik division was considering an off-road vehicle instead of the Z1, so be grateful that their decision to go with the roadster may have saved us from the X5 for a few years.