Alpina Creators’ Family Launches Bovensiepen Spider Roadster: Frank Stephenson Design and a 99-Car Run

The Bovensiepen family, which ran the Alpina tuning house for more than half a century, has unveiled an exclusive, low-volume roadster called the Bovensiepen Spider. The new car is built on the outgoing G29-generation BMW Z4 M40i sports car, features a completely original body designed by legendary designer Frank Stephenson, and packs a tuned 435-hp inline-six. The company plans to hand-build just 99 of them.

A New Life Without the Alpina Brand, With Stephenson’s Touches

Media outlets often mistakenly credit the project to Alpina’s “founders,” but the brand’s patriarch, Burkard Bovensiepen, died in 2023. His sons, Andreas and Florian, run the family business. After the rights to the Alpina trademark passed to the BMW Group, the brothers kept designing one-off cars under their own surname — Bovensiepen.

The Spider is the third model from the new brand, following the Zagato coupe and the 05 GT. The car’s exterior was reworked almost from scratch: the body panels were designed with help from Frank Stephenson, the designer behind the McLaren P1, Ferrari F430, Maserati MC12 and the first BMW X5. The car sheds the sharp creases of the production Z4 in favor of smooth, sculpted forms in the tradition of classic open grand tourers.

435 Horsepower and a Brand Put to the Test

Under the hood, the 3.0-liter turbocharged gasoline engine from BMW’s B58 family carries over. According to the official Bovensiepen brand site, engineers reworked the intake system with a Ram Air scoop and optimized the exhaust path:

• Output rises from a base 340 to 435 hp, while torque climbs to 580 Nm;
• 0–100 km/h takes 4.2 seconds;
• The standard speed limiter moves to 260 km/h, and with the optional Performance Package the ceiling rises to 295 km/h.

The chassis gains retuned adaptive dampers and additional helper springs in the rear suspension, while the sport package adds underbody braces and an aluminum rear differential cover with pronounced cooling fins.

According to BimmerToday, the roadster starts at €115,500 including taxes in Germany, with the first customer deliveries due in late Q1 2027. Next to the limited-run Bovensiepen Zagato at €370,000, the new Spider is considerably more affordable, serving as a test of the Bovensiepen name as a standalone car brand.