BMW Z4 is at the end of its run, but the roadster’s platform is in the process of being given a highly exclusive second life. Bovensiepen Automobile has unveiled the Spider, a limited-production two-seat roadster based on the BMW Z4 M40i.
The new model is a more powerful version of BMW's 3.0-litre turbocharged straight-six engine producing 435hp and 580Nm of torque. Only 99 hand-built examples will be made, so the Spider is a very low-volume performance roadster.
Bovensiepen is the company founded by the family behind Alpina, the BMW-focused performance and luxury brand acquired by BMW. The Spider is the third model of the company and follows its earlier Zagato and 05 GT projects.
BMW Z4-Based Spider gets 435hp
At the heart of the Bovensiepen Spider is a 3.0-litre turbocharged inline-six engine based on the BMW Z4 M40i engine. Bovensiepen has modified the intake and exhaust systems, including an additional ram-air channel and sports exhaust.
The result is 320kW, which is 435hp, and 580Nm of peak torque. The power is sent to the rear wheels through an eight-speed ZF automatic transmission. Unlike the Z4 M40i, the Spider is only built with the automatic gearbox.
The roadster can go from 0 to 100 km/h in 4.2 seconds. Its standard top speed is 260 km/h, and an optional Performance Package can raise the maximum speed to 295 km/h, according to reports.
The Spider weighs in at around 1,585kg. Bovensiepen has made changes to the cooling system and chassis to allow for the extra performance from the engine in addition to the increased output.
Bespoke Design And Chassis Upgrades.
Though the Spider remains the same size as the BMW Z4, its exterior has been extensively redesigned. The car was designed by designer Frank Stephenson and features a new front splitter, distinctive front-fender vents, side skirts, redesigned rear diffuser and an integrated rear spoiler.
The roadster rides on 20-inch forged alloy wheels wrapped in Michelin Pilot Sport 4S tyres. Bovensiepen has also revised the suspension, including revised dampers and longer auxiliary springs at the rear axle.
The braking system can be improved with an optional high-performance setup with larger brake discs and four-piston front calipers. We also have chassis and cooling upgrades as part of the Performance Package.
The Spider has a more bespoke interior than the standard Z4. Buyers can choose premium Lavalina leather and Alcantara on a variety of interior items. A numbered plaque will also be attached to every car that will be in production.
Only 99 Bovensiepen Spiders will be built
The biggest talking point is the production number. Bovensiepen is going to hand-build only 99 examples of the Spider.
The car is priced at €115,500 in Germany, including local VAT. That’s a lot more expensive than the BMW Z4 M40i based on which it’s based, but the Spider is a very special, bespoke performance car rather than a regular-series BMW model. Deliveries will begin in the first quarter of 2027.
The timing is also important as BMW has ended production of the Z4. BMW had announced the Z4 Final Edition as the final production version of the model, and Z4 production was due to be over in March 2026. The last Z4 was delivered in May 2026 from the production line in Austria.
The Bovensiepen Spider therefore arrives after the end of the Z4 production rather than as an official BMW replacement for the roadster.
For enthusiasts, the Spider combines the familiar rear-wheel-drive two-seat roadster layout with extra power, custom design and a very limited production run. Just 99 examples are planned worldwide, so the model is likely to remain a rare sight on the road.
The first customer deliveries are expected in early 2027, marking the next chapter in the saga of the Z4-based roadster, even though BMW itself has already closed the book on the model.
