Automakers are constantly trying to reduce the weight of their vehicles to improve fuel economy. They shave off a few pounds here and there by using lightweight materials and other means.

That’s the reason Michael Arbaugh, interior design chief for Ford, recently declared the compact disc antiquated technology and proposed that the CD player be jettisoned from the dashboard to save about 5 pounds per car.

Five pounds might not seem significant when a vehicle can weigh from 3,000 up to even 10,000 pounds. But automakers have to consider every possible option to conform to stringent new federal fuel-economy standards.

By 2016, the U.S. fleet average for automakers must attain 34.1 mpg for all vehicles, compared with 27.5 mpg for passenger cars and 23.5 mpg for light trucks in 2010. By 2025, automakers must achieve a corporate average fuel-economy (CAFE) standard of 54.5 mpg -- nearly double the current requirement.

Arbaugh pointed out that ditching the in-dash CD player would not only shed precious pounds from a vehicle’s overall weight, but also free up valuable dashboard real estate that could be used for other features. “That's oceanfront property when you are talking about the center stack,” Arbaugh was quoted by the Detroit Free Press as saying at an event in Detroit last week.

"I think anybody under 30 is probably using all MP3 devices,” Arbaugh added. “They don't buy CDs."

Arbaugh is correct about the CD's plunge in popularity. The medium slipped 21.4 percent in dollar sales in 2011 from the previous year, according to the Recording Industry Association of America trade group. Compare this with a 12 percent increase in dollar sales of music-single digital downloads, according to the RIAA. (Vinyl LPs led every available recorded medium, with a whopping 44.4 percent increase in dollar sales, although don’t expect to see a car record player any time soon.)

Why would anyone bother with bringing clunky CDs into the car these days? If the iPod and other MP3 players fatally wounded the compact disc, then the recent proliferation of new forms of music in the car courtesy of cloud-connected smartphones delivered the coup de grace.

Instead of being limited to a dozen or so songs that fit on a disc -- or even thousands of songs on an iPod -- you can have a whole world of music at your fingertips with, say, Pandora Internet radio, which is now becoming common in many new cars. BMW and MINI both offer the streaming music service Mog, and Ford recently announced a partnership with NPR so that drivers with the automaker's Sync system can access public radio content through the dashboard interface using their smartphones.

If you have a smartphone and a car with Bluetooth audio, you can wirelessly stream almost any cloud-based audio content from a smartphone to a car’s radio, although you have to use the small controls on the phone’s screen. And, of course, there’s always regular old terrestrial radio (emphasis on the "always"). Even it has received an upgrade with HD Radio.

Considering that up until last year, Lexus was the final holdout among automakers when it came to including a cassette player in the dash, it’s just a matter of time before the CD player also becomes a dinosaur. Would you ditch the one in your dash?

Doug Newcomb has been covering car technology for over 20 years for outlets ranging from Rolling Stone to Edmunds.com. In 2008, he published his first book, "Car Audio for Dummies" (Wiley). He lives and drives in Hood River, Ore., with his wife and two kids, who share his passion for cars and car technology, especially driving and listening to music.