Autoleads PC9-404 harness adaptor + PC5-90 aerial adaptorThis adaptor will enable you to replace your factory fitted head unit with an aftermarket model.It converts the cars power and speaker plug into a standard ISO connection, suitable for all aftermarket head units.This amplified harness adaptor will allow you to install a car radio of your choice with out cutting any of the existing car wiring. This lead comes supplied with 2 RCA connections (as seen in the picture above) to connect to your unit. Please make sure that the unit you are fitting as at least 1 RCA pre-out if you intend to use this lead. An ISO version of this lead is also avalible from our shop.Fits vehicle models including:AUDI A8 1994 - 2004 BOSE REAR AMPLIFIED UNITS This adaptor accepts RCA preamp inputs. Head units with speaker-level outputs only should use adaptor part reference PC9-401.To activate rear speakers, the blue & White wire on the Red mini ISO plug also needs to be connected to the Blue wire coming off of the New Head Unit (marked Amp Remote). In order to turn on the booster on the PC5-90 aerial adaptor the blue wire on the booster also needs connecting to the Blue wire off the New Head Unit. Use this harness where you have four wires in the Brown ISO connector.The above list of vehicles is a general guide and cannot be guaranteed in all cases.To ensure compatibility, we recommend that the vehicle connector pictured above is compared to the actual connector on your vehicle