Here are some in-car entertainment technologies that you might encounter:

Dolby? Digital: The state-of-the-art 5.1-channel surround format - i.e., five full-range channels (left, center, right, left surround, right surround) plus a low-frequency (bass, or sub-woofer) effects channel (the "0.1") - experienced in the cinema and in DVDs, digital television (HDTV and SDTV) and games. Dolby Digital technology in the car can be incorporated into rear-seat entertainment systems featuring DVD-Video players.

Dolby Pro Logic? II: Pro Logic II converts two-channel stereo into natural, richer surround sound and can be incorporated into car sound systems to transform conventional stereo into an exciting new listening experience. Pro Logic II works with any high quality stereo source, including CD, FM radio, cassettes, XM or Sirius satellite radio, and MP3 files.

MLP? Lossless: The core audio technology behind DVD-Audio, the highest-quality audio format available today, MLP Lossless technology enables studio master disc-quality audio to be encoded on an optical disc, with no loss in quality. MLP Lossless provides the listener a sonic replica of the original studio master tapes during playback, so the listener hears music exactly as it was recorded in the studio, with bit-for-bit clarity and accuracy. DVD-Audio offers sonic resolution that is 1000 times better than CD quality.

Dolby Headphone: Dolby Headphone technology accurately simulates, through any standard set of headphones, the experience of hearing a 5.1-channel speaker system properly set up in a listening room. The annoying, fatiguing "in the head" effect that plagues headphone listening is gone. In the car, Dolby Headphone technology enables rear-seat passengers to enjoy their favorite entertainment without disturbing the driver.

dts?: An alternative sound technology to Dolby Digital and Pro Logic II, dts can be found on some DVD-Video players and DVD discs.

Logic 7?: An alternative sound technology to Dolby Pro Logic II, Logic 7 is found in several new vehicle models but does not offer its technology to aftermarket products.