Make sure your MMI system is 3G+ system before purchase. Please press the bu on of "SETUP" or "Menu", then choose version, read value from the line mark with the le er. the correct format is : HN+_xx_xxxxx or HN+R. | Simply plug into your cars existing Phone/Media socket. Plug and Play with no installation after you connected first time! | Please check your MMI system whether is the 3G+ system, if not, please do not purchase. Compatible with A1 A3 A4 A5 A6 A7 A8 S3 S4 S5 S6 RS6 S8 Q5 Q7 with original MMI 3G+ system. V,W must with MDI Adapter and original radio navigation system RCD-310/RCD-510/RNS-310/RNS-315/RNS-510/RCD-550/RNS-810/RNS-850. | Hi-Fi Aux Output: Bluetoot-h 5.0 Hi-Fi lossless aux transmission for crystal clear phone calls and music.It does not support sk and control music playback using original steering wheel. | Bluetoot-h 5.0 EDR Technology:Made easy route your phone through your car speakers.