Android Auto & Wireless Android Auto Stereos for your 2001 A4

CD Receivers play CD's. They may also have USB and auxiliary inputs, SD card slots, bluetooth for Hands-free calling and audio streaming.

DVD Receivers play music and videos from DVD and CD discs, They may also have USB and auxiliary inputs, SD card slots, and bluetooth for Hands-free calling and audio streaming.

Digital Media Receivers, commonly referred to as "mech-less" receivers, Digital Media receivers do not play CD's. To play music, they rely on music stored on a USB drive, SD card, and built-in Bluetooth.

Digital Multimedia Receivers are simply Digital Media Receivers with the ability to play video from your phone or storage device such as a USB drive or SD card.

GPS Navigation Receivers typically have all the features of a DVD or Digital Multimedia Receiver but also have built-in GPS that doesn't require the use of a smartphone.

Single DIN: 1 DIN dimensions will work with all single DIN installation kits we have to offer. Single DIN radios are the most common size for after-market stereos.

Single DIN slot with flip-out screen: The DIN stereo includes a retractable, flip-out screen. Before purchasing, make measurements to be sure there is no interference with dash accessories such as A/C vents or shift levers.

Single DIN slot with a larger face: Standard single DIN size, but the display is larger then the standard single DIN size. Due to the nature of the larger face, problems may arise when installing in particular vehicles. These stereos are great for single DIN slots where you want a larger screen.

1.5 DIN: This size is very uncommon in vehicles, however this size opening is most commonly found in Chrysler and Chevrolet vehicles.

Double DIN: Approximately 4-inches in height, this size is becoming more common every year. Prior to 2000, this size was typically only found in Japanese vehicles such as those made by Honda or Toyota. Now, it is becoming more popular for many vehicles to be fit with a Double DIN opening.

RCA Composite Inputs
These are your typical red, white, and yellow RCA composite cables that are common among devices with audio and video inputs. The red and white cables are dedicated for audio. The red cable is for the right channel and the white is for the left channel. The yellow cable is specifically for the video signal. Because this type of auxiliary cable contains 2 channels of audio, it will support stereo sound.

3.5mm
This is commonly referred to as a mini-jack or a headphone jack. It is a 3.5mm plug that transfers audio only. There is a right and left audio channel on the plug which allows for stereo sound playback.

3.5mm AV Input
These plugs look similar to the common 3.5mm mini-jack, however they carry a third channel dedicated for video.

Optional
This means that an auxiliary input is possible, but only with the use of an optional accessory. These optional adapters will sometimes use the CD Changer port or other port on the back of a unit that might restrict the use of other expandability features. These accessories are typically sold separately.

RCA Composite Outputs
These are your typical red, white, and yellow RCA composite cables that are common among devices with audio and video inputs. The red and white cables are dedicated for audio. The red cable is for the right channel and the white is for the left channel. The yellow cable is specifically for the video signal. Because this type of auxiliary cable contains 2 channels of audio, it will support stereo sound.

If "Yes", then the aftermarket stereo is compatible with steering wheel remote controls. If an additional accessory is required for the steering wheel controls to work properly, a compatible piece will be listed.