Check the listing for details. For VW Caddy 4 DU Car Radio Adapter Steering Wheel Buttons Cable Plug. Condition: New, Made in Germany. Listed at 132.16 USD. Any existing sound system (Dynaudio, FENDER .....) is activated by the adapter (the sound system amplifier is switched on). However, in this case we need a picture of the radio plug in the vehicle before purchasing, as an additional adapter may be necessary for the signal transmission from the radio to the sound system amplifier. So please send us a picture of the radio plug before purchasing. ...your partner for car audio, multimedia, navigation, alarm systems and positioning systems. ACR-Hof has been one of the leading specialist retailers in Upper Franconia for almost 25 years. With our large product selection and many years of experience, we will work with you to find the optimal system for your vehicle. In our specialist workshop, we install all devices in your car or classic car, com.