1.Easy to install (step 1: put the plug into car's USB & AUX 3.5 socket;step 2: part of car need to choose Audio AUX model for play music before the step 3; step 3: connect the bluetooth adapter by cell phone/ipod/device to play music; 4. Please restart cell phone to connect the adapter if did not success at first time.2.Purchase Notes: this bluetooth adapter does not support simultaneous charging via USB and streaming of music. does not with handsfree feature because the safe driving law not allow. does not with volume control unit button. dose not support change songs from the iDrive system/ steering wheel. the playlist will not be displayed on the car screen a little part cell phone need update a new soft version to compatibility this adapterAudio was modification may be will not work with this adapter3.Blue LED Light Up: bluetooth mode (USB port charging function off); Red LED Light Up: USB mode (Bluetooth transmission function off) you can charge your device, or use the USB function to listen music (note that few MMI system don't support USB function)4.Vehicle compatibility: BMW 1/3/5/6/7 series (2004~2016) and BMW X1 X3 X5 X6 (2006~2013) and Mini Cooper R55, R56, R57 (2007~2016)(Not fit have got the Dashboard navigation system/screen models), NOT with Z4 or E46.( Also fit for Most of vehicles/ home appliance audio with USB/AUX IN interface Bluetooth transmission function)(please contact with us get help if got any unsatisfied with the item, thank you!)5.This adapter fits BMW and MINI cooper models with AUX IN and USB (S6FLA) ports and BMW's without an in dash navigation system/screen.(this bluetooth adapter with not much of functions, but the Sound stable and the Quality will better than other FM channel bluetooth transmission product)