Audi wants the name “e-tron” to become synonymous with its electric drive prowess, as quattro is to all-wheel-drive and TDI to diesels. It unveiled its second “e-tron” vehicle at the North American International Auto Show. This latest concept showcases the considerable advances Audi has made in the few short months since the first e-tron appeared at the Frankfurt show last fall. While not destined for production, the e-tron is a rolling lab and provides insight into what we can expect from Audi in a few years .