BY MARTON PETTENDY | 19th Apr 2006
That's right, it's been four and a half long years since the Munich maker's wild Z3-based M Roadster and M Coupe were discontinued here, but now BMW has redeemed its failure to produce an M version of the controversially styled but far more complete Z4 convertible from the outset by releasing a new-generation M Roadster as part of a facelifted Z4 range.
Of course, you'd expect us to say the newest M model, in true BMW style, is a thoroughly complete and fitting addition to the M stable, thanks to a sufficiently unique interior with M seats, M instruments and M highlights, and an aggressive M bodykit with quad-pipes and specific 18-inch alloys, as well as beefier M brakes and suitably lowered, firmer, lighter suspension with more negative camber and wider wheel tracks.
Oh, and the deletion of the heavy run-flat tyres found on other Z4s (the M makes do with BMW's M Mobility System - read: can of goo).
But as the first taste of M power in the stiffer, more refined and, dare we say it, more grown-up Z4, this M Roadster is both a fitting flagship for the Z4 range and a convincingly capable successor to the raucous Z3 M cars.
Not that it's lost any of it raucousness.
Indeed, with the M3's masterful 3.2-litre six-cylinder stuffed beneath its long, sculpted bonnet, the Z4 M Roadster is among the quickest M models ever built.
Discounting BMW's ingenious V10-powered M5, which stops the 0-100km/h clock at a rapid 4.7 seconds, the Z4 M is in fact two-tenths quicker to 100 than the 85kg-heavier M3 itself and its 0-100 sprint time of five seconds flat is proof this is one of the wildest production cars ever built. BMW also admits it laps the Nurburgring faster than M3.
In typical M fashion, however, the Z4 M also offers supreme driveability, delivering bucket loads of torque from practically anywhere in its rev range - along with a top-end rush (all the way to 8000rpm!) that many other performance cars can only aspire to.
Matched with the sole transmission option of a six-speed manual (BMW's clever SMG self-shifting manual gearbox, which a surprising 80 per cent of M3 owners have specified since its 2001 release, doesn't fit in the Z4 transmission tunnel), the hottest Z4 Roadster M also offers an extra ratio over its five-speed manual-only Z3 M forebear.
As such, while it's still electronically limited to top speed of 250km/h, it gets there quicker courtesy of more tightly packed ratios, and the lack of SMG ensures it's still a purist's sports car.
In short, an M engine finally realises the full potential of the Z4's more rigid, better balanced chassis to create a totally different, more nimble and even more involving driving experience than the M3. And with the top down, it's an aural sensation.
BMW is quick to point out that, at a trim 1410kg, the M Roadster is up to 175kg lighter than some of its convertible rivals. It also claims Z4 has the highest body stiffness in its class, virtually eliminating "body tremble" and helping it achieve a respectable four-star European crash test rating.
A 10mm-lower ride height and significantly firmer springs compared to garden-variety Z4s made the M's ride quality firm bordering on harsh on the sub-standard Northern NSW roads chosen for the launch.
But the Z4-M chassis never flinched, revealing not a hint of scuttle shake and feeling every bit as solid as, say, the SLK, which has long been a benchmark for structural rigidity.
But the Z4 M is more than a better-sounding, more rapid, topless alternative to the superlative M3 coupe.
Just as no M model has BMW's active steering, BMW has ditched the springy, vague electric power steering forced upon owners of lesser Z4 variants, giving us the first taste of a conventionally-steered Z4.
And the result is astonishing. Hydraulic power steering brings a whole new dimension to newest Z4, whose driver knows at all times where the front wheels are pointing and who is unencumbered by the lack of feedback - without any reduction in turn-in response - offered by the other Z4s.
So while its new-generation 3 Series-based suspension makes it more forgiving than its Z3 forebear, conventional steering also makes it more communicative than its Z4 bretheren.
If electric steering is the Z4's Achilles heel, then the lack of it makes the M Roadster both the most complete Z4 yet and a performance roadster that befits BMW's long history of quick convertibles - as well as a real dark horse within the M stable.
Throw in all of the updates wrought in the Z4's midlife facelift - such as the latest-generation stability control system, extra equipment, new technology like adaptive brake lights and minor interior/exterior revisions - and a $7500-lower pricetag than its predecessor, and the new M Roadster makes a pretty convincing argument.
The bad news is only 30 examples will head Down Under this year.
If the first Z4 M Roadster is any guide, we can't wait for the lighter and even more rigid Z4 M Coupe. In the meantime, welcome back, M Roadster - we've missed you!