Red Bull was experimenting with an all-electric formula one car at Spa on Wednesday, publications reveal.
Germany's Auto Motor und Sport and Italy's Autosprint say the reigning world champions' electric prototype was in fact a 2013 Red Bull RB9 sporting a 2014 nose.
But the real novelty was its propulsion -- an all-electric motor to power the car in and out of the pitlane 'box' as the mechanics practiced pit stops.
After a practice stop, Autosprint correspondent Alberto Antonini reveals, the mechanic in the cockpit pushed a button, a reverse warning 'beeps', and the car lurched backwards to be ready for another stop.
"This is the new Formula E," Auto Motor und Sport correspondent Tobias Gruner quoted a Red Bull mechanic as joking.
He added that among the fascinated observers in the Spa-Francorchamps pitlane on Wednesday was none other than FIA technical delegate Jo Bauer.