Car MP3 connection kits with USB,SD, Bluetooth+Aux in Features:Car MP3 connection kits with USB,SD, Bluetooth+Aux inPerfect CD sound quality, ... no FM noisy. 16GB USB flash and SD card ... car models only set dip-switch and alternate corresponding. Compatible with: OEM Radio: VW, Audi, Skoda, Seat, BMW, Mazda, Nissan, ...