A roadster from the company that used to be Alpina
Bovensiepen has revealed the Spider, a two-seat roadster built on the BMW Z4 and limited to 99 hand-built cars. It is the third model from Buchloe since the family put its own name on the building, after the 05 GT and the Zagato-bodied version of it.
The timing is the first thing worth noticing. BMW has stopped building the Z4, and the M version that enthusiasts asked about for six years never happened. Bovensiepen has built it anyway, at a price BMW would have struggled to ask.
What Bovensiepen has confirmed
- Engine: 3.0-litre turbocharged straight-six, the B58
- Power: 320 kW, 435 PS
- Torque: 580 Nm
- 0 to 100 km/h: 4.2 seconds
- Top speed: 260 km/h, or 295 km/h with the Performance Package
- Power to weight: 3.6 kg per PS
- Production: 99 cars
- Price: from 115,500 euros in Germany, including VAT
- Deliveries: from the end of the first quarter of 2027
- Fuel consumption: 8.8 l/100 km combined, 199 g/km CO2
For reference, the Z4 M40i it starts from makes 340 PS. The Spider adds 95.
The parts that are actually Bovensiepen
Frank Stephenson drew the exterior work, which is a name that carries weight for a car in this class: the first BMW X5, the modern Mini, the F430, the P1. The bodykit is a front splitter, vented wheel arches, side skirts and a rear diffuser rather than a reskin.
Underneath, Bovensiepen quotes a less restrictive intake with a ram-air duct, a stainless steel sports exhaust with four tailpipes, recalibrated shift times for the ZF eight-speed, retuned dampers and longer auxiliary springs at the rear axle. Wheels are forged 20-inch in three finishes, wrapped in Michelin Pilot Sport 4 S, 255/35 front and 295/30 rear. A four-piston brake upgrade with 395 mm front discs is on the options list.
Inside, Vernasca leather with Alcantara seat panels is standard and a full Lavalina hide interior starts at 9,916 euros, which is the kind of number that tells you what sort of company this still is.
The numbers that will confuse you
Several outlets have run this car at 429 bhp and several at 443 hp. Both are the same car. Bovensiepen quotes 320 kW and 435 PS, and the conversions land either side of it depending on which horsepower a publication means. We have used the manufacturer's own figures.
Bovensiepen has not published the drive layout, the standard brake specification or a UK price. The Z4 is rear-wheel drive, but we are not going to state that as a Spider specification until Bovensiepen does.
Where it sits
At 115,500 euros this is roughly Porsche 718 Spyder RS money for a car built 99 times by a company most buyers have to have explained to them. That is the whole proposition, and Buchloe has made a living on exactly that proposition for fifty years. The difference now is that the badge on the nose is the family's, not a brand BMW owns.
Sources: Bovensiepen, Spider model page; Bovensiepen Spider Revealed: 435 HP, 99 Units, €115,500 (BMWBlog, 10 September 2026); Bovensiepen Spider: exclusive roadster or an expensive Z4 makeover? (GTspirit, 11 September 2026). Photographs: Bovensiepen.