The Bovensiepen Spider is a 430bhp BMW Z4 with Alpina DNA
A new company built by the family behind the original Alpina has turned the BMW Z4 into a 430bhp spider with styling from McLaren P1 designer Frank Stephenson. Only 99 will be built.
If you remember the old Alpina, before BMW took over the name, you’ll probably have a good idea of what the Bovensiepen Spider is trying to do.
Bovensiepen is the new company built around the family behind the original Alpina, and it takes its name from founder Burkard Bovensiepen. While BMW now controls the Alpina brand itself, Bovensiepen continues to modify BMWs in much the same spirit, and the latest example, based on the BMW Z4, is the Spider.
It gets more power from BMW’s 3.0-litre turbocharged straight-six, a revised chassis, bespoke bodywork and an interior that can be customised with plenty of leather and Alcantara. Just 99 will be built, with prices starting from €115,500, around £99,000 at current exchange rates, and customer deliveries are expected to begin in 2027.
How much power does the Bovensiepen Spider have?
The Spider uses BMW’s familiar 3.0-litre turbocharged straight-six, but Bovensiepen has increased output to 430bhp and almost 430lb ft of torque, up from 355bhp and 369lb ft in the standard BMW Z4 M40i.
Power is sent through an eight-speed automatic gearbox to the rear wheels, with 0-62mph taking 4.2 seconds. That’s only three tenths quicker than the standard car, but the Spider can reach up to 183mph when fitted with the optional Performance Pack.
The performance upgrades go beyond simply turning up the boost. Bovensiepen has fitted an unrestricted air intake with an additional ram-air channel, a larger intake silencer and a new exhaust system designed to reduce back pressure and give the straight-six a deeper sound. Cooling has also been upgraded, the suspension gets tuned dampers and longer auxiliary springs at the rear, and buyers can specify larger brakes with four-piston callipers.
What does the Bovensiepen Performance Pack include?
The Performance Pack adds a few more changes for buyers who want to make the most of the Spider’s extra performance. There’s an aluminium rear differential cover with larger cooling fins, an underbody V-brace to increase chassis stiffness, and the higher 183mph top speed.
None of this turns the Z4 into a completely different car. That’s rather the point. Old Alpina was known for taking BMWs and making them faster, more luxurious and more individual without losing the character of the original car, and Bovensiepen is clearly trying to continue that approach.
Who designed the Bovensiepen Spider?
The Spider’s exterior has been redesigned by Frank Stephenson, the designer behind the McLaren P1 and a number of other high-profile performance cars. This isn’t his first work with Bovensiepen either, he already collaborated with the company on its 05 GT, based on the BMW M5 Touring.
The Spider gets a new front splitter, side skirts, rear diffuser and rear spoiler, along with lightweight 20-inch forged alloy wheels. The changes are relatively subtle, which suits the Bovensiepen formula, this isn’t a BMW Z4 wearing a body kit for the sake of attracting attention. Inside, there’s more scope for personalisation too, with leather and Alcantara available in a range of combinations.
How much does the Bovensiepen Spider cost?
Prices start at €115,500, around £99,000, before customers start adding options, and that buys one of just 99 cars.
That makes the Spider considerably more expensive than the BMW Z4 it’s based on. But you’re not just paying for a faster Z4, you’re paying for a limited-production car with bespoke engineering, unique styling and something the standard car has lost along the way, real exclusivity.
The BMW Z4 has always been a slightly unusual choice in the sports car market, and Bovensiepen’s version pushes that idea further. For buyers who remember what Alpina used to represent, that’s probably the whole appeal.
Bovensiepen Spider verdict
The Spider doesn’t need to reinvent the Z4, and I don’t think it’s trying to. It just needs to make the old Alpina formula work for a new generation, more power, more presence, more leather, without losing what made the original cars interesting in the first place. On the evidence so far, that’s exactly what Bovensiepen is doing.
At just under £99,000 for one of only 99 cars, this was never going to be a rational purchase next to a standard Z4 M40i. But rational was never really the point of Alpina, old or new, and if you’re the sort of buyer who remembers what that badge used to mean, this is about as close to it as you can currently buy.