Not the least of it are body shells made of carbon-fiber reinforced plastic (CFRP) mounted atop an aluminum rolling platform carrying the powertrains and crash structures.
BMW has said that in due course, the plug-in cars' advanced technology would migrate into its higher-volume mainstream production models.
Now we know what one of those models will be: the next generation of the BMW 7-Series full-size luxury sedan.
The company announced at a 7-Series technology preview last week that it would use a lightweight Carbon Core structure for the big sedan.
The CFRP elements in the body shell save fully 286 pounds (130 kg) over a comparable high-strength steel structure.
In cutaways showing the new body structure, much of the passenger cage appears to be made of CFRP--including some elements backed with steel to form specific members.
BMW had said in 2012 that it would use carbon fiber in the structure of a new 7-Series, following reports that Mercedes-Benz will build a version of its next-generation E-Class with a carbon-fiber structure that could save as much as 770 pounds.
That car has not yet been released, but we can expect additional details this year or next.
Following the industry trend, the new 7-Series will use a number of downsized and turbocharged engines, an eight-speed automatic transmission.
While the company didn't say anything about a plug-in hybrid model, the lineup is bound to include one or more--possibly using the company's next-generation Power eDrive system.
Competitor Mercedes-Benz already offers a plug-in hybrid version of its own S-Class large sedan, and is steadily spreading the system across other vehicles in its range.
Meanwhile, the Cadillac CT6 plug-in hybrid model launched today at the Shanghai Motor Show uses a far larger battery pack and will likely provide far higher electric range than any of the German competitors.
Other innovative features on the new 7-Series will include the first use of gesture control for certain functions, essentially a driver or passenger making hand motions in the air.
It will also include Remote Parking control, which the driver will activate using a new display key after getting out of the car.
That will make the next BMW 7-Series the first production vehicle that can park itself, including in spaces so tight that a human couldn't open a door to exit.
For more details on the upcoming 7-Series, Green Car Congress has summarized the full BMW announcement.