The BMW Z4 may have officially reached the end of the road, but it isn’t quite ready to disappear. Bovensiepen, the company founded by the family behind the original Alpina, has given BMW’s discontinued roadster a second lease of life with the new Spider. It gets more power, sharper suspension, a subtly reworked body and plenty of leather, with production limited to just 99 examples.
The Spider is based on the Z4 M40i, which means it is powered by a 3-litre turbocharged straight-six sitting behind the front axle and driving the rear wheels. Bovensiepen has worked over the engine with a freer-flowing intake featuring an additional ram-air channel, a larger intake silencer and a new sports exhaust. The result is 429 bhp and 579 Nm, up from the M40i’s 382 bhp and 500 Nm and that’s quite a healthy gain.
That extra shove gets the Spider from 0 to 100 kph in 4.2 seconds, while the standard car is limited to 259 kph. Tick the ‘Performance Pack’ option and the top speed rises to 295 kph. The pack also brings improved differential cooling and an aluminium rear differential cover with larger cooling fins, along with an underbody V-brace to add rigidity to the chassis.
Bovensiepen hasn’t stopped at more power. The suspension has been retuned with revised dampers offering greater compression control at low damper speeds, while longer auxiliary springs at the rear are intended to sharpen the car’s response. The Spider rides on lightweight 20-inch forged wheels wrapped in Michelin Pilot Sport 4 S tyres, with more powerful brakes available as an option.
The gearbox, however, is strictly automatic. Unlike the Z4 M40i that was offered with a six-speed manual in some markets, the Spider uses BMW’s eight-speed ZF automatic and sends its power only to the rear wheels.
Visually, Bovensiepen has resisted the temptation to turn the Z4 into something completely unrecognisable. The design work comes from Frank Stephenson, the designer behind the McLaren P1, Ferrari F430 and first-generation BMW X5. The front gets a new splitter and revised side vent treatment, while the side profile gains new side skirts and distinctive 20-inch wheels. At the back, there is a new diffuser, quad exhausts and an extended boot-lid spoiler. The changes are subtle, but that is part of the appeal. Rather than covering the Z4 in aggressive aero, Bovensiepen has lowered its visual stance and added just enough detail to make it look more special than the BMW it started life as.
Inside, the standard Z4 cabin gets a much more luxurious treatment. The seats are trimmed in Vernasca leather, while the steering wheel uses Bovensiepen’s more exclusive Lavalina leather. Alcantara is used elsewhere, and buyers can go much further through Bovensiepen’s Saddlery personalisation programme, with options including personalised headrests, custom embroidery and an Alcantara-lined boot.
There is an interesting bit of history behind the Spider, too. The original Alpina team created the Roadster S based on an earlier Z4 around two decades ago, so this new car effectively brings that idea back using the latest-generation Z4 as its starting point. The difference is that this one cannot be called an Alpina.
BMW acquired the Alpina brand, while the Bovensiepen family continued independently under its own name. The Spider is therefore a Bovensiepen product rather than a BMW Alpina, even though its mechanical foundations remain unmistakably BMW. Only 99 Spiders will be built, with deliveries scheduled to begin in 2027. Prices start at €115,500 (Rs 1.2 crore Europe, before taxes), making this a considerably more expensive way into a Z4 than before, but exclusivity and personalisation are very much part of the package.
