Although it couldn't quite surpass the Miata, the Z3 was still a solid roadster in its own right.
The Mazda MX-5 is a hard act to follow, and the BMW Z3 didn't quite do it. There have also been better entry-level sports cars from German brands, including the Z3's successor, the Z4. So why include it? The Z3 was a runaway success for BMW, and this is because it was the one car in its niche which best embodied all of the elements of the classic roadster. And as for not quite being the roadster the MX-5 is? That's ok, there can only be one king.
The Z3 was designed by Joji Nagashima, a Japanese designer working for a German company to create the answer to an American-designed Japanese version of a British car. Still with me? The car used a shortened version of the 3 Series E36 platform, which would come to be known as E36/7 for the Z3 roadster. BMW guessed (correctly) that the US market would be the most important one for the Z3, just as it had been for basically every other roadster of note. It therefore seemed best to build the Z3 in the US, and their Spartanburg, South Carolina plant was given the task of the car.
It debuted as a 1996 model, and the press hated it. The rounded nose drew scorn from the fashion-conscious, and the 1.9-liter 138-horsepower four-cylinder engine was deemed woefully inadequate for anything with a BMW badge on it. Then it appeared in "Goldeneye". It can't be said for certain that this appearance as a Bond car was what did it, but every single 1996 Z3 (15,000 in total) that the factory was able to build was already sold before the first delivery was even made. Perhaps BMW had figured that the most recent Bond movies prior to "Goldeneye" hadn't done very well, and that they had never sold that many Aston-Martins anyway.
Whatever it was, their manufacturing capacity proved completely unable to deal with the publicity of a relatively cheap BMW in a movie that was #1 at the box office. It might not have made fans of the M3 happy, but the Z3 had a lot going for it. The rounded nose might not have been a favorite, and the vents in the front fender might have been a bit silly, but the overall proportions of the car are dead on. The long hood and short deck are classic roadster, and it was the same length as a 1974 MGB. The E36/7 chassis brought with it the stiffness and handling ability of the 3 Series, which were beyond reproach.
In all fairness, the power and the interior weren't really what you'd expect in a BMW, but they were perfectly adequate for a classic-style roadster. And the plastic rear window... well, ok, that was unfortunate. An odd footnote in the history of the Z3 was the Z3 Coupe. This went beyond the addition of a simple hardtop, and turned the car into a sporty-looking shooting brake. This was a controversial look, to say the least. Some people loved it, myself included, but I'm not so delusional as to think that this is an attitude shared by everyone.
A higher-performance M version of the car was made as well, which was available in both roadster and coupe body styles. This was certainly more powerful, getting the 240 horsepower 3.2-liter E52 straight-six engine out of the E36 M3. At least, this was what the American version got. Quite a few M aficionados felt cheated by this, since the European version of the car got the Euro-spec E36 M3 engine, the 321-horsepower S50 B32. Still, even the US-spec M offered the kind of power which people had always wanted from the Z3. The problem was, this kind of power was expensive, and by 2000, potential M Roadster buyers were generally more taken by the Porsche Boxster S.
Though it had started off strong, the Z3 ultimately struggled to keep sales up. It was a fine roadster, but it was having a harder and harder time justifying a price tag which was so far above that of the Mazda MX-5. It was replaced in 2002 by the Z4, a car which was much more BMW than the Z3. The Z4 had a nicer interior, better electronic goodies, and more power. Lots more power. This included a properly insane and tire-shredding M model, even for the US market. It has proven to be a much more popular model, and this effectively proved what had always been the Z3's problem, it was made by the wrong company.
People just have certain expectations of a BMW, and sticking to a classic roaster formula, no matter how well it's executed, just isn't what people want in a Bavarian drop-top. The MINI Roadster isn't a roadster in the classic sense, but it does demonstrate the value of BMW having a cheaper sub-brand. BMW's only real mistake in making the Z3 was their lack of an appropriate badge for it.