SPY PICS: First glimpse of Alpina B5 in action

German tuning house Alpina is the destination of choice for BMW aficionados who want faster, sharper, more engaging yet discreet cars.

And that's exactly what customers can expect with the new Alpina B5, a modified version of the BMW 5 Series, which has been spied undergoing high-speed testing at the Nordschleife (the northern loop of the Nurburgring) in Germany.

With the Alpina B4 already confirmed for Australia, and expected to arrive here in coming months, it's entirely possible the B5 will also sell through select BMW dealerships for the local market.

Based on the new BMW 5 Series (G30), the Alpina B5 will deploy a subtle new look thanks to re-sculpted front and rear bumps and side skirts, with new wheels contributing to the understated upgrade.

The B5 pictured testing at the Nurburgring features a lower ride height courtesy of a re-calibrated chassis, and the bespoke quad exhaust system hints at numerous powertrain modifications too.

Several engine options are expected to be fettled by Alpina for its latest creation, with turbo-petrol inline six and V8 engines likely to be given a few extra herbs and spices.

BMW is also plotting a new quad-turbo diesel six-cylinder engine to replace its current diesel king, the triple-turbo 280kW/740Nm beast.

Having boasted a "wolf in sheep's clothing" ethos since the brand began, tracing its history back to 1965, Alpina's latest creation has a conservative appeal that builds on the 5 Series' new look.

Not to be confused with Renault's reborn sports car brand Alpine, Alpina is a German tuning house that takes regular BMWs and modifies them.

Unlike some of the world's most famous aftermarket tuning houses, Alpina is technically a manufacturer, and is recognised by German authorities as such. Not unlike HSV's relationship with Holden, some Alpina models are fully assembled at BMW factories.

Alpina builds around 1700 bespoke cars per annum and has a strong motorsport pedigree, probably most famous for developing the striking BMW 3.0 CSL Coupe, a car that won the 1973 European Touring Car Championship.

That car was immortalised in a wild concept, the BMW 3.0 CSL Hommage, in 2015.

The new BMW 5 Series is expected to arrive in Australia from March 2017 and if the Alpina B4 generates a solid response from customers, it's possible the B5 will be offered here too, possibly in wagon form /spy-pics-bmw-5-series-alpina-wagon-for-geneva-103305 as well as the sedan.