Luxury Sport Convertibles Comparison

When it comes to small, open sports cars of German persuasion, two manufacturers have long been fighting for market share: BMW and Porsche. The Z4 and Boxster S are both tangible, driveable proof of a significant difference in each firm's approach to pop-top two-seaters.

While BMW uses the front-engine/rear-drive configuration it has utilized in just about all of its sports cars, Porsche puts the engine aft of the driver--a hallmark since the company's birth. Each roadster packs a six-cylinder engine: BMW's in an inline configuration, Porsche employing its equally hallmark, horizontally opposed layout.

The new-for-'03 Z4 replaces the successful Z3. During its seven-year production run, the Z3 was criticized for its tight cabin, power shortage (except in M form, of course), and suspension and steering, which fell short of real sports-car responsiveness and linearity. BMW tackled these concerns with the Z4 (like the Z3, it's built at BMW's Spartanburg, North Carolina, plant). The flame-surfacing design is by no means a hit with everyone, but the Z4 represents a bold move in a new direction--and it has a more masculine look than did its predecessor.

The Z4's interior is roomier than the Z3, thanks to a longer (99.7-inch) wheelbase. Legroom is substantial, and the footwell has been enlarged. A fully adjustable steering column allows almost any-size driver to tailor the left-seat position, the better to gaze across a well-laid-out, crisp-edged, and nicely finished instrument panel.

Few convertibles can boast a soft top as easy to raise and lower as the Z4's. One button does it all; raising takes 10 seconds, lowering only 8.5. When raised, the top is free of flutter and drafts, while the blind spot is minimized with a large, glass rear window. The top structure proved tight and draft free.