While spectacular to drive, it was hard not to feel a bit hollow, since Audi had just confirmed it wasn't going to put the sleek red vehicles into production.
Not for the first time, Audi has changed its mind.
Audi's original concern was that the car's range of around 130 miles simply wouldn't be sufficient for the way it expected owners to use their cars.
The company hinted as much at its event in Berlin, where engineers explained that at the car's limited top speed of 124 mph--eminently achievable on Germany's de-restricted Autobahn highways--the car would drain its battery in 20-30 minutes.
Changes to the car's packaging and battery technology have allowed Audi to extend the e-tron's range to 250 miles--almost double that of the prototypes.
It should also be more cost-effective than before. Among the headline figures of Audi's dozen-or-so e-tron prototypes was a price tag of $1.3 million. While this doesn't include the amortization of costs you'd see over a proper production run, it illustrates the expense of making a carbon-fiber bodied, bespoke electric supercar.
There's another purpose to the R8 e-tron, too: as Audi pushes its e-tron technology on other vehicles, the electric supercar ensures Audi has a flagship 'halo' model for its plug-in drivetrains. Mercedes' SLS AMG Electric Drive and the upcoming BMW i8 are other examples of this halo vehicle attraction.
Only a wealthy few will get to own Audi's electric supercar, but for the rest of us it's yet more proof that EVs can be just as exciting--if not more so--than their gasoline counterparts.