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Crux BMW, Mercedes, Porsche and Smart Radio Replacement Module (SWRBM-57)

Install an Aftermarket Radio in select BMW, Mercedes, Porsche & Smart Vehicles and Retain Steering Wheel Controls

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Crux BMW, Mercedes, Porsche and Smart Radio Replacement Module (SWRBM-57)

Install an Aftermarket Radio in select BMW, Mercedes, Porsche & Smart Vehicles and Retain Steering Wheel Controls


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The CRUX SWRBM-57 is a Multi-CAN radio replacement interface for select Mercedes-Benz, BMW, Porsche & Smart vehicles. It facilitates the integration of an aftermarket radio to retain factory features with CAN-bus based vehicles. This enhanced interface is also pre-programmed for retention of steering wheel controls.

General Features:

  • Aftermarket Car Stereo Installation Interface
  • For select Mercedes, BMW, Porsche & Smart Vehicles
  • Retains factory features with aftermarket radios
  • Retains factory-installed amplifiers (Analog amplifiers only)
  • Retains Steering Wheel Controls via built-in, pre-programmed interface
  • With navigation outputs (Reverse gear, Illumination and Speed signal)
  • Provides Accessory Power ( 2A MAX )
  • Authorized Internet Dealer
  • 1-year Manufacturer's Warranty

Compatible Vehicles

Use Quadlock harness for:
  • BMW
    • 2007-2013 - 1 series (E81/82/87/88)
    • 2005-2012 - 3 series (E90/91/92)
  • Mercedes-Benz
    • 2004-2010 - A-Class (W169) with Quadlock
    • 2004-2010 - B-Class (W245) with Quadlock
    • 2006-2011 - R-Class (W251)
    • 2000-2006 - C-Class (W203)
    • 2005-2011 - M-Class (W164)
    • 2007-2012 - C-Class (W204)
    • 2004-2008 - SLK (R171) Non Fiber-Optic
    • 2001-2002 - E-Class (W211)
    • 2009-2012 - E-Class (W212)
  • Porsche
    • 2002-2010 - Cayenne
    • Boxster with Quadlock
    • 911 with Quadlock
Use Iso Harness for:
  • Mercedes-Benz
    • 2004-2010 - A-Class (W169) with Audio5
    • 2004-2010 - B-Class (W245) with Audio5
    • 2000-2003 - C-Class (W203)
    • 1999-2000 - E-Class (W210)
    • 1999-2002 - CLK-Class (W208)
    • 2001-2004 - SL-Class (R230)
  • Smart
    • 2007-2013 - Fortwo

Check out the SWRBM-57 User Manual

Harness Features

Vehicle Sound System
This refers to what kind of sound system the vehicle has. Premium audio systems are generally name brand systems (such as JBL, Bose, Rockford Fosgate, etc) that have been installed inside a vehicle when it leaves the factory. Often they more advanced systems, complex wiring, factory amplifiers, and other features that can make installing aftermarket component difficult.
Standard Sound
Main Harness Function
Different installations on different vehicles require different harnesses. This type is what the harness is considered. Each wiring harness we sell serves a purpose such as installing an aftermarket car stereo, integrating an aftermarket amplifier with your factory car stereo, connecting Bluetooth to your factory car stereo, and more.
Install a Car Stereo & Retain the Factory OEM Amplifier
Additional Harness Features
The various features that the wiring harness provides to your car stereo and/or audio system.
Chime Retention
Provides Vehicle Speed Sense
Retained Accessory Power (RAP) Retention
Retains Steering Wheel Controls
Compatible Vehicle Make
Allows you to view only items that are compatible with your vehicle's make. Does not guarantee that it will work with your vehicle year or model.
Compatible Vehicle Make and Model
The model of vehicle that this vehicle specific product is designed for. Please keep in mind that engine variations can affect the compatibility of the products.
BMW 1 Series
BMW 3 Series
Mercedes Benz A Class
Mercedes Benz B Class
Mercedes Benz C Class
Mercedes Benz CLK-Class
Mercedes Benz E Class
Mercedes Benz M Class
Mercedes Benz R Class
Mercedes Benz SL Class
Mercedes Benz SLK-Class
Porsche 911
Porsche Boxster
Porsche Cayenne
Smart Car

Premium Harness Features

Factory System Amplification
This refers to the factory sound system and whether the item is compatible with amplified or non-amplified systems.
CAN-BUS Compatible
CANBUS Ballasts ensure compatibility with ALL vehicle makes and models without the need for additional accessories. In addition, they have built-in Anti-Flickering Capacitors to help prevent lighting issues caused by voltage spikes and drops by stabilizing the power.
Compatible with Aftermarket Navigation Systems
This means that the item is made to work with aftermarket systems with navigation. Typically, this means that the harness has wires that are used with GPS navigation systems, such as VSS wires and others. Please read the product description for full details of this feature.
Chime Retention
This means that the harness is able to retain the vehicles chimes.

Warranty and Return Policy

Parts Warranty Duration
1 year
Labor Warranty Duration
1 year
Warranty Provider

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Browse 2 questions
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Will this work on my 2005 MB e320 cdi sedan? I am installing a pioneer 280bt
A shopper on Oct 5, 2016
· Add Answer · I Have This Question Too (0)
I bought an 8" joying unit for my 2004 cayenne. I am looking for the fiber optic adater for it, can bus and wire harness. Is this unit what I look for?
Hugo r on Sep 17, 2016
· Add Answer · I Have This Question Too (0)

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Sonic Electronix Wiring Guide

Wiring Diagram Legend

Warning: The image depicted shows the resistance change when wiring multiple subwoofer terminals. Please refer to your subwoofer's owner's manual for the proper wiring of its terminals. Sonic Electronix, Inc. is not responsible for damage caused to your audio system or vehicle due to improper installation. Please call tech support at 1-877-289-7664 if you require additional assistance.

Product Name: Crux BMW, Mercedes, Porsche and Smart Radio Replacement Module (SWRBM-57)