Like earlier’s Audi TT, BMW’s first successful foray into the roadster market came in the 1990s with the Z3. The Z3’s styling was less aggressive and more organic than the original “Future Roadster” – the Z1 – had been, but initially motivation wasn’t much better. However, when BMW decided to stuff the E36 chassis full of the higher-power M-product motors, they instantly created a hit. Rear drive only with a singing inline-6 and attached to a manual transmission, they were affordable sports cars that offered a very high fun quotient even if they were not the most refined product, style or substance-wise.
At the same time that the M Roadster and M Coupe debuted in North America, planning was already underway for the Z3’s replacement. The new E85 Roadster and E86 Coupe debuted as a fresh face to replace the 90s-era Z3 in the early 2000s, but almost immediately the styling was considered controversial. There were hard edges, curves and cuts integrated into the exterior, and the traditional driver-oriented dashboard was gone, replaced by a more modern flat-cockpit layout. Much like the original Z1, it didn’t look like anything else on the market at the time, and reception was mixed.
Dynamically, though, it was hard to argue that the Z4 wasn’t a vast improvement in refinement over the Z3. The rear suspension was updated with a new multi-link setup which handled power (and bumps) significantly better than the outgoing E36 chassis with E30 bits. A stiffer structure meant more overall composure. And though the interior remained plastic-heavy, the new generation of dashboards looked much more upscale and modern than the dated 90s pieces. Yet the biggest change lay at the end of the run, as it had with the Z3, as starting in 2006 BMW installed the legendary S54B32. Providing 330 horsepower to the rear wheels and trick M-differential via a 6-speed manual, the limited production M Roadster and M Coupe also corrected one of the perceived flaws of the normal Z4 lineup by retaining a hydraulic steering setup. More aggressive exterior styling was met by a refreshingly simple and less gimicky interior than the Z3 had. For some 3,041 original owners, this was Roadster perfection, and today on the used market they’re a steal relative to their exclusivity and performance: