Fans of open-top BMWs have a rather special new option to consider. The Bovensiepen Spider has arrived with 429 hp (320 kW), more performance and a substantially more exclusive feel than the BMW Z4 on which it is based.
Bovensiepen is the new marque established by the family behind legendary BMW tuner Alpina, and its latest creation takes the recently discontinued Z4 and pushes it into a very different league.
A BMW Z4 With A Bovensiepen Makeover
The Spider follows Bovensiepen’s Zagato coupé and its wild 05 GT estate, but this time the focus is firmly on the traditional two-seat roadster.
Andreas Bovensiepen’s fascination with this type of car stretches back to his involvement with the BMW Z8 development programme in Munich during the late 1990s. That influence is clear here, with the Spider designed around the idea of a responsive, engaging and relatively lightweight open-top sports car.
The exterior was developed with designer Frank Stephenson, whose extensive CV includes work on the McLaren P1. Changes include a new twin-lip front splitter, a prominent ducktail rear spoiler and a redesigned rear diffuser.
Rather than completely reinventing the Z4’s shape, Bovensiepen has focused on making it look lower, sharper and more distinctive.
429 HP From The Familiar Straight-Six
Under the bonnet sits BMW’s familiar 3.0-litre turbocharged straight-six, but it has received some serious attention.
While the engine produced 335 hp (250 kW) in the Z4 M40i, the Bovensiepen Spider delivers 429 hp (320 kW) and 580 Nm of torque.
That is enough to send the roadster from 0 to 100 km/h (0 to 62 mph) in 4.2 seconds.
Specify the optional Performance Package and top speed climbs to an impressive 294 km/h (183 mph), making this the fastest interpretation yet of BMW’s compact two-seat roadster.
Bovensiepen has modified the intake to improve airflow and fitted a new sports exhaust system. Cooling has also been upgraded, while Performance Package cars gain an aluminium rear differential cover with larger cooling fins designed to better handle sustained high-speed driving.
Unfortunately for manual gearbox fans, the six-speed transmission offered late in the Z4’s life hasn’t made the cut. The Spider uses the familiar ZF eight-speed automatic transmission instead.
Chassis Tweaks And Forged Wheels
The Spider sits on unique 20-inch forged wheels featuring ten elongated double spokes. Their lightweight construction helps reduce unsprung mass while maintaining the comfort expected from a more luxurious roadster.
Michelin Pilot Sport 4S tyres provide the grip, while the dampers have been recalibrated to work with the new wheel and tyre package.
Inside, Bovensiepen has moved the Z4 further upmarket with extensive full-grain leather and Alcantara trim.
Just 99 Bovensiepen Spiders Will Be Built
Production will be limited to just 99 cars, making the Spider considerably rarer than the BMW model underneath.
Of those, 40 are planned in Sapphire Black, 25 in Sanremo Green, 20 in Skyscraper Grey, nine in Thundernight and five in Frozen Grey II. Customers wanting something different will also be able to commission their own colour.
Pricing starts at €115,000 (approximately R2,159,430), placing the Spider firmly into serious performance-car territory.
Deliveries are expected to begin in early 2027.
With the BMW Z4 now out of production, the Bovensiepen Spider is an interesting send-off for the platform. More power, limited production and extensive chassis and design changes turn what was already an entertaining roadster into something far more exclusive.
