“Even without the
 coveted BMW badge
 you’d still want to
 own a superb new Z4”

The 'Ultimate Driving Machine'. BMW's catchphrase is almost as well-known as its blue-and-white roundel. But it won't be the memorable advertising tagline or the pedigree badge gracing its thrusting nose that will sell the Z4. It will be the genuine substance of the rear-wheel drive Z4 Roadster's impressive dynamics.

We tested the Z4 in range-topping 3.0-litre form and make no mistake, it's a real corker. If you like driving you'll truly love getting behind the wheel of BMW's latest two-seater sports car.

First off, those lines. BMW call the edgy sculpted styling 'Flame Surfacing'. Whatever, it works. Our test car was finished in a non-metallic Bright Red that totally harmonized with the flamboyant lines. And — judging by the reaction of just about everybody else —
visually a red Z4 is, as they say in the fashion world, the new black.

There's so much to like about the Z4 it's hard to know where to begin. Externally the Z4 doesn't so much 'flame' as smoulder. Mean, muscular and masculine with a palpable air of aggression from its long 'basking shark' bonnet and 'wide-mouthed' lower air intake. Cruise down any crowded street, light splintering off the 7-arm double-spoke 17-inch alloys, and you'll spot the meaningful nods of approval as you drift by, along with the lingering stares of desire.

Fresh and decidedly 'cool' on the outside, inside there's a surprise.
The cabin is equally as eye-catching but in a completely different 'minimalist' way. Dominating the cockpit is a full-width lozenge-shaped fascia finished in brushed aluminium that defines the Z4's un-complicated and uncluttered internal symmetry. What's essential is there; what isn't doesn't even get a look in.

A functional, centrally-sited console houses the audio system controls below which is the straightforward air-con switchgear flanked by nice-to-use rotary heater controls. Above them, sited to inform but never distract the driver, is a 6.5-inch anti-glare colour screen for the SatNav that emerges from the top of the dashboard at the touch of a button and can be electrically folded flat when not in use. The screen displays fully scaleable maps of the route and destination alongside other on-board computer and telephone functions. Highlighting the attention to detail is the fact that the screen module can be tilted to the best angle to avoid glare when motoring topless on a bright day. All-in-all, the elegant cabin's a delight to live with.

From the moment you get behind the superb leather-rimmed sports steering wheel with three-aluminium-spokes (a tactile pleasure!) you understand that a keen driver — a real enthusiast — has thought long and hard about the driving environment, making it easy to use and, above all, about focusing on driving.

The ergonomics are spot-on, as is the driving position, helped by a steering wheel that adjusts for both height and reach. You sit a long way back, low down in excellent seats (our test car was fitted with the optional M Sports Seats with adjustable thigh support, available for an extra £475) with plenty of leg room near the Z4's centre of gravity, looking over two individually-cowled dials (speedometer with inset computer display and rev-counter/fuel/temp, both with clear white-on-black graphics) down the long, tapering bonnet. Even before you move off you just know you're in something designed for serious driving.

Build integrity and trim materials are both first class, reflecting the brand image, and the flagship 3.0-litre Z4 comes exceedingly well-equipped. Standard kit includes 17-inch alloys, leather upholstery,
8-way electric seat adjustment with a 3 position memory for the driver, automatic air-conditioning, on-board computer, auto-dim rear view mirror, auto lights, rain sensing wipers, a high pressure jet wash system for the headlights, a tyre puncture warning system with 'Run Flat' tyres, remote central locking for the doors, bootlid, fuel tank flip and the storage box between the backrests, heated electric door mirrors, heat-insulated glass, 'move off' central locking, single CD player, sports steering wheel, front and side airbags and the world's fastest fully-automatic convertible roof.

Unseen, but just as desirable, are the electronic driver aids for traction and stability control including ABS, and BMW's M Technic sports suspension.

By its very name the Z4 Roadster is all about top-down motoring. And taking the rays couldn't be simpler. Press a switch and an impressively-fast 9-second striptease later the cockpit is open to the skies. Better still, the top automatically folds away out of sight under a body-colour hard cover behind the twin A-shaped roll-over hoops. The hood is of excellent quality, well soundproofed, with a heated glass rear wind-screen. Raised, it adds hushed refinement to the decent amount of room enjoyed by the Z4's two occupants.

Roof down, the Z4's a good place to be, the neat wind deflector in place between the hoops keeping it all satisfyingly civilised. Do specify the optional heated seats: they're among the best we've encountered and warm your entire back, all the way from your coccyx to the base of your neck. Superb. Incidentally, another thoughtful touch is the dedicated holder in the boot lid for the wind deflector. Good news too is that there's room for a week's luggage in the practical 240-litre boot. Or, depending on your priorities, two sets of golf clubs. An extra 20 litres of space is available if you intend travelling roof up by temporarily collapsing the roof storage box in the boot. A ten-litre storage box between the seats at the rear is particularly handy.

The Z4 comes with a choice of powerplants — all sweet straight sixes — starting with an entry-level 2.2-litre. Middle of the range is a lusty 2.5 which is good for 192bhp, 0-62 in 7 and a top speed of 146mph, which should be fast enough for most drivers. However, who would not prefer to get to 62mph in 5.9 seconds instead? You would? In which case you'll want the 231bhp 3.0-litre, limited to a top speed of 155mph.

All three six-cylinder engines are impressively refined. But once you've driven the 3.0-litre you'll find it hard to justify how you can live without that extra power and performance. Fired up and under way, it's a driver's dream. Silky smooth, impatient to show you how it goes and oozing deep-down torque, it pulls eagerly from low revs. There's oodles of urge for blitzkrieg overtaking without going to the redline, and the fat torque band that serves up 221lb ft of pulling power at 3,500rpm means muscular power exactly where you want it. So much so that at times, particularly soaring along winding country lanes, it seems as if one gear is all you need. You can just leave it in third and the Z4 can be slowed almost to jogging pace yet it will still respond urgently to the throttle as the road opens up, snarling melodiously under determined acceleration.

The Z4 boasts electric power steering but — before the purists throw up their hands in despair — be assured that it works a treat. The new electro-mechanical system controls steering feel and feedback levels by software. Activated by a Sport button on the centre console, DDC — Driving Dynamics Control, previously only seen on cars from BMW Motorsport — alters the throttle pedal mapping for faster accelerator reaction times, and the power steering response for a more direct and dynamic steering response. Unlike hydraulic systems, it uses no engine power thus saving owners one litre of fuel every 250 miles.

Like the creamy six-pot engine, the sweet-action six-speed gearbox
is also first rate — in the Z4 you don't so much change gears as just snick the short throw lever through the gate. On the road the close ratios are well-matched to the 3.0-litre's brawny torque curve, with sixth perfect for long-legged cruising and 85mph coming in at a steady 3,000rpm. The brakes, too, are perfectly suited for some serious motoring. Ventilated discs serve up good feel and, more pertinently, immediate and fade-free stopping power.

Anybody buying a high-performance sports car is not going to lose any sleep over fuel consumption. And even if they wanted to, they'd be hard pressed to be concerned about the Z4. Even in 3.0-litre guise we recorded a regular 30mpg with motorway journeys frequently showing 40+mpg. The fuel tank takes 12.1 gallons which is good for 500 miles at the official extra-urban 42.8mpg.

Dynamically the Z4 delivers the goods in a manner that instils total confidence. Thanks no doubt to its impressive torsional stiffness — almost three times greater than that of the Z3 it supersedes — the roofless Z4 feels as taut and rigid as a full metal jacketed coupé. The run-flat Bridgestone rubber (225/45s all round) is grippy and handling sharp and superbly composed, with tenacious grip and fine body control that lets the driver place the Z4 precisely and corner neutrally. The almost perfect 50-50 weight distribution helps. Push it hard and, enhanced by the road feel communicated via the electronic steering, the comfortably firm M sports suspension does a great job of ironing out road blemishes and contributes to a fluent and entertaining drive.

Keeping all Z4s on the straight and narrow — with a supporting rather than guiding hand — is BMW's all-singing and all-dancing Dynamic Stability Control system. DSC manages traction losses and counters slip through bends. Actually, only truly reckless driving is likely to invoke DSC intervention in the first place so most drivers will be best served leaving it switched on to do the job it was designed to do. The only button you really want to push is the Sport button next to the gearlever to 'weight up' the steering and sharpen the drive-by-wire throttle response.

The Z4 comes with a battery of electronic safety systems but you 'canna cheat the laws of physics!' and whatever electronic wizardry manufacturers' install in cars to protect drivers from themselves, things can still go pear-shaped. Therefore, it's reassuring to know that should the worst happen while you're in a Z4 you'll be well protected with
four airbags and reinforced windscreen pillars that form a frontal roll bar and a pair of roll-over hoops permanently fixed in place behind the seats.

In the EuroNCAP test earlier this year the Z4 turned in the best test results ever seen in the Roadster segment. The EuroNCAP assesses the level of risk of driver and passenger injury on a sixteen-point scale — the Z4 scored 15.64 for a frontal impact and 16.00 for a crash from
the side. These are also the best results ever recorded by this test procedure.

So although the Z4 doesn't have a fixed roof construction, the level
of passenger stress in the event of an accident is even lower than in most modern vehicles with a solid roof.

Additional safety features include the Z4's run-flat tyres. Their tyre faces make it considerably easier to control vehicle reactions in the event of a sudden puncture, and it is even possible to continue driving for 90 miles following a complete loss of tyre pressure. And since
80 per cent of all punctures are preceded by a slow pressure drop,
a puncture warning indicator is fitted as standard to warn the driver well in advance of any serious damage occuring.

Another BMW innovation fitted as standard to the Z4 is the two-level brake light. In a real emergency stop, additional LEDs are activated in the brake lights as a strong visual warning to following vehicles.

The bumpers also merit a mention. Both front and rear are designed
to completely regenerate in small impacts of up to 2.5mph, with deformation elements of the chassis designed to absorb impacts up to 9mph without damaging the body structure itself. Not only could this help you save face in the car park, but it could save you money as well!

In its sharp new clothes, the Z4 will appeal to those looking for tomorrow's car today. But for those who know enough to look beyond the edgily styled outer skin to the substance below, it will be a no-brainer. The Z4's a convincing, well-executed sports car, impressively well equipped and immensely rewarding to drive and own. The Ultimate Driving Machine is back. Go ahead — you know you want one.

BMW Z4 3.0i Roadster | £31,325 Maximum speed: 155mph | 0-62mph: 5.9 seconds Overall test MPG: 30mpg | Power: 231bhp | Torque: 221lb ft Visit BMW's website