Bovensiepen Spider revealed as BMW Z4-based roadster

Bovensiepen has revealed the Spider, a limited-production two-seat roadster based on the BMW Z4 M40i. It is the third model from the Buchloe-based company and follows the Zagato and 05 GT, with production capped at 99 hand-built examples. The Spider gets bespoke exterior and interior changes, along with revisions to its suspension, cooling and exhaust systems. Orders are now open, with first deliveries scheduled for the end of the first quarter of 2027.

Bovensiepen Spider: Exterior

The Spider retains the Z4’s basic roadster proportions, with a long bonnet, rear-set cabin and short overhangs. Its exterior was developed with designer Frank Stephenson, who also worked on the Bovensiepen 05 GT. Changes include a gloss-black front splitter with twin tips, front fender vents, side skirts, a rear diffuser and an integrated rear spoiler. It also gets 20-inch forged wheels.

The roadster measures 4,334mm long, 1,864mm wide and 1,304mm tall. It has a kerb weight of 1,585kg. Of the 99 Spider examples, 40 will be finished in Sapphire Black, 25 in Sanremo Green, 20 in Skyscraper Grey, nine in Thundernight and five in Frozen Grey II.

Bovensiepen Spider: Interior

There are no major changes to the interior design compared with the BMW Z4, with the differences mainly focused on upholstery, trim and personalisation. The two-seat cabin gets Vernasca leather upholstery, Alcantara seat panels and a Lavalina leather steering wheel. A heated steering wheel, Comfort Access and a Harman Kardon surround-sound system are standard.

Optional interior upgrades include full-leather upholstery, a leather dashboard and Alcantara trim for the A-pillars, wind deflector and roll-bar cover. Bovensiepen’s in-house saddlery can also add personalised headrest embossing and embroidery. Each car gets a numbered production plaque, while boot capacity is 281 litres.

Bovensiepen Spider: Powertrain

The Spider is powered by a 3.0-litre turbocharged inline-six B58 engine producing 435hp and 580Nm, making 95hp and 80Nm more than the BMW Z4 M40i, which produces 340hp and 500Nm. Bovensiepen has revised the intake and exhaust systems, with the former gaining an additional ram-air channel and the latter receiving changes to improve flow. Power is sent to the rear wheels through an eight-speed ZF automatic gearbox.

The Spider takes 4.2sec to accelerate from 0-100kph and has a top speed of 260kph. The optional Performance Package increases the top speed to 295kph and adds a milled aluminium rear differential cover with larger cooling fins and an underbody V-brace. It also brings revised dampers and longer rear auxiliary springs.

The Spider marks Bovensiepen’s return to the roadster format, following the Alpina Roadster S based on the BMW Z4 (E85). The new model is based on the BMW Z4 (G29) M40i and is positioned as a two-seat sports car with limited, hand-built production. Bovensiepen says the Spider is aimed at enthusiasts of lightweight sports cars and roadsters.