This morning I’m at a small test track around 50km outside Stuttgart for an Audi technical presentation on the advances the company is making in lightweight design.

Unexpectedly, one of the test cars is the technology mule for the Quattro concept that Audi unveiled last year. It may look like an ordinary A5 coupe, but it’s actually built around a bespoke aluminium spaceframe chassis, with an aluminium skin and carbon reinforced plastic bonnet and bootlid.

It uses a 400hp version of the TTRS’s five-pot engine, driving a 60/40 rear-biased quattro drivetrain through a six-speed manual ‘box. With the stock A5 coupe interior, this prototype weighs in at an impressive 1400kg. With a planned lightweight interior and the 150mm reduction in wheelbase used for the Quattro concept, that all-up weight could drop to just 1300kg.

This development car is part of the process of proving the Quattro concept ahead of it being given the green light by the Audi board and I’ve just stepped out of it after three quick and punchy laps of this small circuit.