The Porsche Boxster versus BMW roadster rivalry is certainly not a new one, as two different iterations of Z3-based M roadsters have been offered to Americans during the Boxster's tenure. The first one bowed in 1998 with the 240-hp, 3.2-liter six from the E36-based M3. Then, after the E46 M3 debuted for 2001, BMW briefly offered a 315-hp version of its 3.2-liter in the same Z3-based body. (That six also was installed in the often-overlooked 2001 M coupe.) Like those Z3-derived ragtops, the new Z4 M hews to BMW's classic roadster recipe: long-nose, short-deck styling, a lightweight, rear-wheel-drive chassis, and a rev-happy, front-mounted engine. It's a formula that dates back decades, to the 1928 Wartburg Sport and the 1935 BMW 315, and one that has produced some very handsome and desirable automobiles.
But the shark-nosed Z4 has not been as well received as the Z3, even though it offers crisper handling, an avant-garde interior, and a stronger brace of six-cylinder engines. We were anxious, then, to see what a full-body treatment in the M division's powertrain, suspension, and aesthetics spa could do for the South Carolina-built roadster. Could it rescue the Z4 from also-ran status? And could it topple the revered Boxster ... Read full article