Back in 1994, when I heard the rumours about a BMW roadster from European magazines, I expected to see a real driver's car that provide unmatchable driving fun. After its launch in 1996, I am a little bit disappointed - that does not mean that BMW Z3 is a bad car, no, definitely not, but because we used to rate BMW cars as the best drivers' cars in the world.

Maybe we cannot over-expect Z3. In order to reduce cost, BMW installed it with the previous 3 series rear suspension (semi trailing arms) and assemble it in south USA. The former limits its handling ability and the latter leads to a lower build quality, though BMW will never admit.  

Also because of cost problem ( why always this problem? Z3 is not cheap! ), Z3 has to satisfy with the existing engines from the 3 series, i.e., 115hp 8 valves 1.9 litres four, 140hp 16 valves 1.9 litres four, 193hp 2.8 litres six and 321hp 3.2 litres six ( which calls "M Roadster" instead of "Z3M" ). The four cylinders, with which the majority Z3s will install, are less sweet than MGF's VVC engine and Alfa Spider's 2.0ts unit. On the contrary, the 2.8 litres version is very strong. It can outperforms all rivals bar the Porsche Boxster, and delivers lovely character. Nevertheless, higher price means that it may face tough competition from the brilliant Boxster and Mercedes SLK.

Road tests found Z3 has a very solid chassis and grippy tires, thus fast attack on bends would feels nothing other than secure. Nevertheless, it lost the involving steering that appeared in 3 series and 5 series, and lacks the adjustability that made Mazda MX-5 so thrilling. To BMW, this disadvantage is more serious than its strange look. 
 

Facelifted Z3

The first to notice is the exaggerate wheel arches delivering even more muscular look than the current car. Otherwise other changes of details are quite minor - reshaped bumper and boot lid, bigger tail lights, larger double kidney grille, improved seal in the roof and a mildly redesigned center console in the cabin.  

Rear track has been stretched by 64mm although there is no obvious improvement in handling base on the early impression. After all, the old semi-trailing arm rear suspensions and lack of chassis rigidity were not given any modification, so the Z3 will face a hard life when the Audi TT Roadster come, let alone Honda S2000. 

Like the 3 Series, the production of the 140hp 16 valves 1.9 has been phased out and replaced by either the 118hp 8-valve 1.9 litres or 150hp 2.0 litres six cylinder with Double Vanos. 2.8 and M-power 3.2 continue serving the top models.
 

M-Roadster

The objective of M Roadster is quite mystery. By slotting the 3.2 litres 321hp straight 6 from the M3 into the Z3 chassis (updated: now the new M3 engine, but with 325hp instead of 343hp because of more restricted exhaust system due to limited space), further with bigger tyres and other necessary tuning, BMW has created a roadster which could blew all other competitors away in terms of performance. However, is it necessary and appropriate ? I don't think so. 

Remember, the Z3 is based on the 3 series Compact platform, which sacrifice some handling excellence to in favour of lower cost. Such chassis, especially in such a small dimension, seems to be too hard to cope with the M3 engine. Moreover, those ask for pure roadster fun will find Z3 2.8 to be the better choice because of the relaxing manner, while those demand pure handling will prefer other rock-solid close-top sports cars.  

A roadster with supercar performance seems to be too impractical. 
 

Z3 Coupe and M Coupe

Traditionally, we know a hardtop coupe must be more rigid than its cabriolet version, that means under hard cornering the chassis twist or bend less. If the chassis twist or bend less, the suspensions pick up points and geometry also vary less, so the wheels remains perpendicular to the road surface. In contrast, open top car's chassis are usually weaker, thus the suspension geometry varies a lot under hard cornering or when riding on bumps, this leads to non-neutral steering response and reduction of grip.  

Nearly all open top cars handle worse than their hard top versions, with the exception of Porsche 911. In the BMW M Roadster, the problem is quite serious, because neither its chassis nor its two-generations old semi-trailing arm rear suspensions were designed to handle the 321 hp M-Power straight six. (updated: now the new M3 engine, but with 325hp instead of 343hp because of more restricted exhaust system due to limited space) By the way, you must know the Z3 was originally a competitor to the Mazda MX-5 Miata Roadster.  

The relatively weak chassis deteriorate M Roadster's handling as well as ride. Although BMW set the suspensions stiffer to compensate the lack of chassis rigidity, the M Roadster was still criticised as "excessive bump steer", "rides very hard", "vibration transmit to the dashboard thus causing the steering wheel shakes", "heavy steering wheel but responds slowly", "lack of agility and sensitive" blah blah blah.... Autocar even said the TVR Chimaera is more pleasant to drive yet more refined !  

Now, BMW finally cured the faults by introducing a hard top version of the M Roadster - the Z3 M Coupe. In fact, the Z3 Coupe is also available in 2.8 litres form, just like the Z3 Roadster, but here we concentrate on the more exciting M Coupe.  

Despite of lack of official figure, we know the torsional rigidity of M Coupe's chassis is doubled. Without altering suspensions and steering, the stronger chassis alone magically transformed the car into a much more exciting sports car. Vibration in steering wheel has gone. Bump steer has been eliminated. Steering becomes more responsive and feels more communicative. Oversteer becomes easily obtainable. In short, handling is vastly improved. It rides better, too.  

You might dislike its odd hatchback design. It doesn't matter to me, because I used to dislike the styling of Z3. Someone may accuse it of imitating the classic MGB GT. Who care ? BMW is the boss of Rover and MG !  

Originally, the design team wanted to add two small seats. Unluckily this was eventually turned down because the rear suspensions engage such space. Remember, when BMW designed the Z3 Roadster, they put the engine and seats backward in order to achieve 50 / 50 weight distribution. Therefore there is virtually no space left between the front seats and rear suspensions.  

Anyway, no rear seats means a very big boot space - 410 litres ! Go to supermarket to buy a week's food ? Well, your wife might not need those 321 horses under the bonnet !