10Fans of wind in the hair driving, behold: the 429bhp Bovensiepen Spider is here. It’s a special, more luxurious version of the recently retired BMW Z4, created by the new marque from the founders of legendary BMW tuner Alpina. “Ever since I was part of the BMW Z8 development team at BMW in Munich in the late nineties, purist roadsters have fascinated me,” said Andreas Bovensiepen, one of the tuning company’s managing directors. “Cars that are light, responsive and therefore a great joy to drive. They appeal to all the senses and put a smile on the driver’s face.” This is only Bovensiepen’s third model, following on from its 603bhp Zagato coupé, which was based on the BMW M4, and the 789bhp 05 GT estate that took a BMW M5 Touring and carefully massaged it, with the help of McLaren P1 designer Frank Stephenson. The new design elements on the Spider, such as its twin lip front splitter with the Bovensiepen name, large ducktail spoiler and rear diffuser, were also crafted in collaboration with Stephenson. The goal from the outset was to give the last Z4, which went out of production earlier this year, a more sporty, elegant and timeless design. The 20-inch Bovensiepen forged wheels, which feature ten long double spokes, are designed to reduce weight, enhancing the roadster’s agility and comfort. They’re wrapped in a set of Michelin Pilot Sport 4S tyres, while the car’s dampers have been retuned to make the most of the high-performance rubber and boost responsiveness. Beneath the Spider’s long bonnet is the 3.0-litre twin-turbo straight six that used to make 335bhp in the Z4 M40i. But Bovensiepen has fettled it to deliver 429bhp and 580Nm of torque, which is enough grunt for 0-62mph in 4.2 seconds. Top speed is 183mph with the optional Performance Package, making this the fastest ever version of BMW’s two-seater sports car. The engine’s intake system has been modified for more airflow, and Bovensiepen has added a new sports exhaust system that delivers a sound which is claimed to be “exhilarating”. The company says cooling is better now, too, but the aforementioned Performance Package also adds a new aluminium rear differential cover with larger fans to suit high-speed motorway driving, perfect for Germany’s autobahns. 10Sadly, the Bovensiepen Spider doesn’t feature the six-speed manual that made its way into the Z4 towards the end of its run. Instead, it gets the standard ZF eight-speed auto. Meanwhile, the rest of the interior has been retrimmed in more luxurious full-grain leather and Alcantara. Discerning drop-top fans can order a Bovensiepen Spider now, with prices starting from 115,000 euros – just over £99,000 at the current exchange rate, making it more expensive than a BMW M4 Convertible. You can purchase a BMW Z4 for as little as £7,000 through the Auto Express Buy A Car service. Bovensiepen is only making 99 examples of its drop-top The company says 40 will be finished in Sapphire Black, 25 in Sanremo Green, 20 in Skyscraper Grey, 9 in Thundernight and 5 in Frozen Grey II. However, customers can request a new colour of their choice, presumably for a hefty fee. Deliveries are set to begin early next year, just in time for summer. Don't miss the best of Auto Express on Google! Make us a preferred source. Click here...