Four wheels, two seats and a big engine. It doesn't get much simpler than that. Like any classic roadster, more than half the length is given over to the engine, which is one reason why there's only space enough for a couple of passengers. As to the changes made to this revised MK2 version, well, they don't amount to very much. The headlights include white LED corona rings and a white 'eyebrow' with additional chrome detailing, while in profile, the side gill features chrome detailing and LED side repeater lights. Otherwise, things are much as they were with the original version of this MK2 model Z4, with subtle styling flourishes like the indented 'V' set into the bonnet running like a ribbon snagged on the badge.
Neat detailing then - and neat packaging too. You'd certainly expect the inclusion of a two-piece electro-hydraulic metal-folding roof to have altered this Z4's appearance a good deal more than it has but there are no awkward looks, no tell-tale bulky rear end. BMW's design team could work miracles though and in return for the security of a hard top, you've to accept a couple of significant drawbacks. First, the speed of operation: the top takes around 20s to raise or 21s to lower (about twice as long as the roof on a fabric-topped Audi TT Roadster). At least you can operate it at speeds of up to 20mph though.
The other issue, rather predictably, concerns bootspace. That's fine of course when the roof's up - with 310-litres on offer. When the top's retracted though, that figure falls to just 180-litres - about 25% less than you'd get in a rival Mercedes SLK. Having said that, the Z4 has the advantage of being able to boost its trunk capacity via an optional ski-flap. Thus equipped, you could carry either a couple of sets of short-ish skis or, more ambitiously, a couple of sets of golf clubs. If you find yourself a car whose original owner paid extra for the 'Comfort Access' option, you'll be able to raise the folded roof sandwich slightly to get hold of bulky stuff you might have put in the boot when the roof was up but which otherwise would become trapped there when the roof is down. Many owners will want to avoid this problem by using the 15.5-litre interior storage area behind the seats.
And behind the wheel? Well, settle comfortably into the low-slung seat and it all feels just right, your eyes pretty much on a level with the long vented bonnet in front, tempting you to lift the seat right up to try and see over it. The snug wrap-around dash is lovely and there are some lovely unique-to-Z4 touches like the clustered climate control dials. As you'd expect for the premium money being asked, everything is beautifully built from the highest quality materials. Plus the extra head, shoulder and elbow room that have been built into this MK2 model Z4 design give it an airier cabin feel than some of its competitors.
The overwhelming majority of Z4 buyers in our ownership survey seemed to be extremely happy with their cars. However, inevitably, there were a few issues. One buyer complained of a faulty rear diff, a faulty dual mass flywheel and noisy hydraulic lifters. Another found that a broken roof bracket prevented roof operation. And yet another had initial problems with paint finish and various rattles. There were also scattered reports of minor electrical faults. Look out for all these things on your test drive.
Like all modern BMWs, rather than specifying preselected service intervals, the car's on-board diagnostics indicate when a service is due. It's therefore important to discover when the last service took place and ask to see documentary evidence of this. Make sure the folding hard top mechanism functions exactly as it should and don't be afraid to be utterly pedantic when running through all of the electrical functions. Check the alloy wheels for kerbing damage and make sure the alarm and immobiliser system are functioning properly. Some owners will have specified their Z4s to the nines from BMW's options list and will want to claw back what they've spent. Don't entertain any of it.
(approx based on a 2014 Z4 sDrive 18i) Compared to Mercedes and Porsche, BMW spares are reasonably priced. A set of front brake pads for the Z4 retails in the £25-£55 bracket, though you can pay up to around £75 for a more expensive brand. Brake discs start at around £38 for a pair, though we found pricier brand discs priced at around £90, around £106 and around £141. A oil filter costs £7-£10 and an air filter around £25. For a wiper blade, you're looking at paying in the £7 to £13 bracket, while a drive belt is around £15.
This may be a fashionable roadster but it isn't a car for ladies who lunch. Slip into the low-slung seat and drop the roof and your eyes are virtually on a level with the long, vented bonnet. It certainly feels like the real deal, especially if you've a growly six cylinder engine plumbed in up-front.
The chances are though, that you won't have. Sporting BMWs may have been inseparably associated with six cylinder engines down the years but most of the powerplants on offer in this improved MK2 model Z4 line-up squirt fuel into the quartet of cylinders boasted by a TwinPower Turbo 2.0-litre unit that was offered in three states of tune. The 184bhp sDrive 20i and 245bhp sDrive 28i variants were carried over from the original version of this MK2 model, but in an attempt to snare customers who might otherwise have to settle for cheaper segment rivals like the Mazda MX-5 or the MINI Roadster, BMW introduced a more affordable Z4 starter-variant for this facelifted design, in the form of the 156bhp sDrive 18i.
If at this point, you're expecting us to suggest that less is more, then we're afraid you're going to be disappointed. When spec changes are taken into account, the sDrive 18i will save you very little over the sDrive 20i that 80% of Z4 customers choose, it's no more frugal to run, there's less pulling power on offer and its 7.9s 0-62mph sprint time is a second slower. Arguably the sweet spot in the range though, is occupied by the ultimate four cylinder model, the sDrive 28i, which fires you past the 62mph benchmark in 5.7s on the way to a top speed that has to be reined in at 155mph. The two 3.0-litre in-line twin turbo six cylinder models are similarly restricted, the 306bhp sDrive 35i and the 340bhp sDrive 35is, respectively able to demolish the 0-62mph sprint in 5.2s and 4.8s. There was never a diesel option.
Unlike the 3 Series Convertible, the first car BMW made with a metal folding roof, this Z4 managed to retain the German brand's famed 50:50 weight distribution with the roof up but ironically, it's driving with the roof down and the extra weight over the rear wheels that the rear wheel drive chassis feels most responsive. There's virtually no body roll and in the dry at least, you rarely run out of grip. The brakes are great too. On the downside, the manual gearshift action could be a little smoother and it's a pity that the steering doesn't have a bit more feel though, at least it's accurate and always enables you to place the car precisely. This car has to satisfy coupe and roadster buyers so roof up, refinement has to be peerless: it is. Roof-down of course, it's very different, but many will see the blustery feel as part of the fun of owning a car of this kind.
All Z4s come with BMW's Drive Performance Control system. Here, via focused 'Sport' and relaxed 'Comfort' settings, you can set your car up to your own preferences, just like a race team would on a racecar. That means altering the response of throttle, steering, stability control and even the gearchange times if you've opted for the eight-speed automatic or the full-blown M DCT 7-speed twin-clutch auto transmission that's the only choice for sDrive 35is buyers.
If you've found a Z4 whose original owner paid extra for the Adaptive M Sport Suspension set-up, the Drive Performance Control settings can also alter the suspension settings - and therefore the ride comfort. If you've got this option, then you'll find that an extra 'Sport +' setting is added to the system which lowers the car by 10mm, firming things up still further for racetrack use and offering 10% more driver leeway before the stability control cuts in.
BMW has been building roadsters for over 80 years - and that showed with this improved second generation Z4. It was model that matured extremely well, slowly and methodically developing into an all-rounder that's now tough to beat as a used buy if you're looking for a car of this kind from this era. In fact, we can't help feeling that this is probably the ideal car of its kind for most potential buyers. True, it isn't the driver's machine that, say, a Porsche Boxster can be but it gets close enough for many likely customers to start prioritising the lower pricing and security-minded metal folding roof that come with this BMW.
What it all means is that though the Z4 might not be the first car you look at when choosing a sports roadster, look at it you must. It's just too good not to.