In 60 seconds or less.
That's how Kelley Blue Book presents the 2014 Chevy Volt in this overview video
"KBB.com's brief overview of the 2014 Chevrolet Volt."
The Volt's unique powertrain (EREV) doesn't lend itself well to quick overviews due to the complexity with which it functions, but we think KBB did a decent job in trying to highlight the Volt's features in less than 60 seconds.
The problem with the Chevy Volt (and now the BMW i3 REx) is that effectively marketing such a unique powertrain setup isn't easy. Chevrolet has all but given up on marketing the Volt for some reason.
On the flip side, BMW hasn't even begun to market the i3 REx separately from the i3 BEV. It seems BMW may be leaving the difficult task of explaining precisely how the REx functions to its dealers, which in general aren't capable of performing such a task.