Audi A4 B6/B7 (Typ 8E) 2001-2008 Replaces Symphony Radio Double Din Fascia Panel Fitting Adaptor CT23AU01 My Car You could also use this

You could also use this amplifier in 1-channel bridged mode to power a subwoofer with up to 600 watts RMS

Current Consumption: 47

Connects2 CT25VW07 - VW Golf

Focal Utopia 6WM 6-1/2" component woofer

RMS: 600W Total (300W Each Sub)

Audi A4 B6/B7 (Typ 8E) 2001-2008 Replaces Symphony Radio Double Din Fascia Panel Fitting Adaptor CT23AU01 My Car You could also use thisThese adaptors will convert the non din sized aperture left after removing the factory stereo to a double din size ready for head unit installation. The high quality finish, colour and texture are designed specifically to maintain the original look of your vehicle's interior. Compatible with the following vehicles: Manufacturer Model Note Year From Year To Headunit Connection Audi A4 B6 B7 (Typ 8E) 2001 2008 Replaces Symphony Radio N A Audi Double Din