Comfort is something the 05 GT ought to do well on the road. We won’t know for certain until we drive one in the UK, but the way this revised chassis dealt with the fiendish undulations of the Salzburgring was promisingly languid but underpinned with confident-inspiring control. That said, Bovensiepen ought to offer 20in wheels with a little more sidewall, just to be on the safe side in terms of secondary ride. Unfortunately, a grand total of six laps doesn’t permit much more in the way of meaningful real-world dynamic analysis.
Performance? Monumental; move on. Towards the end of the day, a familiar pattern unfolded during a few spirited laps with one of Bovensiepen’s factory hot-shoes in a Zagato prototype. The 05 GT would have unnerving stability in the big brake zones. It would then turn in beautifully for a big car, only to fall off the back of the Zagato as its nose-y balance and weight counted against it on the way to the apex. Then, once rotated, it would inexorably reel in the smaller coupé on the exit like a Lancaster bomber bearing down on a microlite. It is just monstrous and has the depth of performance and monolithic composure that tends shrink big miles with ease.
Nonetheless, one suspects those who do spend the €51,000 (circa £44,000) or so that Bovensiepen is asking for this conversion will be mainly in it for the aesthetic improvement and the chance to have a truly bespoke cabin. After all, the effects of the uplift in power will be negligible on the road, and at 2555kg the 05 GT offers no weight saving next to the standard M5 Touring. In fact it’s 5kg heavier.
It’ll be interesting to see if the 05 GT can remedy the M5’s slightly stilted B-road ride in the UK, mind. If it can, as well it might on this evidence, then along with all the other modifications, the asking price and seventh-month build time begin to look if not outright alluring then at least palatable. For Alpina’s traditional customer base, added appeal comes in the form of rarity – these days the factory in Buchloe has capacity only for 100 or so of these conversions annually.
Price £144,000 (approx) Engine V8, 4395cc, twin-turbocharged, petrol, plus 195bhp AC synchronous electric motor Power 790bhp Torque 811lb ft Gearbox 8-spd automatic, 4WD Kerb weight 2555kg 0-62mph Less than 3.6sec Top speed 190mph Economy 53.3mpg CO2 124g/km Rivals Audi RS6 GT
