Fiber Optic(MOST) adapter for Mercedes-Benz/Porsche/BMW
  • Model: MOST

Price:   $99.00

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This Fiber Optic(MOST) adapter allows you to retain the factory(Mercedes-Benz/Porsche/BMW) MOST amplifier audio system(Harman/Kardon or BOSE) when installing ANY aftermarket radios. The output from all speakers including subwoofer and premium sound quality. This makes for a nice clean easy install.

When installing this interface into your Mercedes-Benz/Porsche/BMW you must make sure that the fiber optic signal loop is not broken.  If you have other devices which can include original CD Changer, satellite radio, and telephone module they must stay connected so the fiber optic signal loop is consistent.

To identify if you have a fiber optics MOST factory-amplified audio system, you can check the vehicle in a number of ways. Some vehicles will have clear markings on the speaker grills indicating the presence of an upgraded audio system. You can also check with the original order notes/invoice from when the car was purchased from the factory, the upgraded sound system with an amplifier would show on the options list. If unsure, you can call your local dealer with your vehicles chassis number and ask them to check if the vehicle was manufactured with an amplified audio system. If you are not sure, please send the VIN and a photo of existing dashboard of your car to, we will help you to check.

NOTE:  This does NOT support the D2B fiber optic system. If your fiber optic cable has these D2B connectors our MOST interface will not work.

This product has three models for different cars, so please make sure you provide the correct information of your car when place the order to avoid mistake.

Version 1:
Mercedes-Benz CL-Class(2003-2008)
Mercedes-Benz CLS-Class(2003-2008)
Mercedes-Benz E-Class(2002-2008)
Mercedes-Benz S-Class(2003-2008)
Mercedes-Benz SL-Class(2003-2008)
Mercedes-Benz SLK-Class(2004-2008)

Version 2:
Mercedes-Benz C-Class(2005-2008)
Mercedes-Benz CL-Class(2009-2012)
Mercedes-Benz CLK-Class(2005-2008)
Mercedes-Benz CLS(2009-2012)
Mercedes-Benz E-Class(2009-2012)
Mercedes-Benz GL-Class(2005-2011)
Mercedes-Benz ML-Class(2005-2011)
Mercedes-Benz R-Class(2005-2011)
Mercedes-Benz SLK(2009-2012)
Mercedes-Benz S-Class(2009-2012)
Mercedes-Benz SL-Class(2009-2012)
Porsche Boxster(2005-2011)
Porsche Cayenne(2005-2011)
Porsche Cayman(2005-2011)
Porsche 977/911(2005-2011)

Version 3:
BMW 1 Series (E82/E87) 2008-2012
BMW 3 Series (E90/E91/E92/E93) 2006-2011
BMW 5 Series (E60/E61) 2004-2010
BMW X1(E84) 2009-2015
BMW X3(E83) 2003-2010
BMW X5(E70) 2006-2013
BMW X6(E71) 2008–2014
BMW Z4(E89) 2009-2016

Connection map

1. Yellow wire-Positive of battery(usually it is the yellow wire from aftermarket head unit main harness).
2. Red wire- ACC wire(usually it is the red wire from aftermarket head unit main harness).
3. Black wire-GND(usually it is the black wire from aftermarket head unit main harness).
4. RCA audio input-connects to the Front left and Front right audio output of aftermarket head unit
5. Fiber optics plug-connects to the fiber optics plug on your car

Frequently asked questions:

Q.  Can I return this for a refund if I do not like it?
A:  NO.  We warranty the product for one year.  If there are any problems with it, we will replace it with a new one for you.

Q.  Why are there only TWO RCA inputs?
A:  It only supports stereo input from your front Left and front Right RCA audio output.

Q.   If it is only using TWO RCA audio cable how will get sound from all of my speakers?
A:  The MOST interface will convert the TWO RCA audio signal into a fiber optic signal your factory amplifier can understand.  Your Harmon Kardon amplifier will distribute sound to all of your speakers including your subwoofer.

Q.  Can I control fade and balance after this is installed?
A:  You can control only LEFT RIGHT balance since it is only using those two RCA audio cables.  No fading from front to back.

Q.  Does this support steering wheel button controls?
A:  This does not add or remove steering wheel button control.  It only has one function and that is to convert RCA audio into a fiber optic signal the factory amplifier can understand.

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  We offer worldwide shipping service by international
couriers like FedEx/UPS/DHL/EMS/Aramex etc.,
Orders usually be shipped within 1-2 working days and
the tracking number will be sent to you by system email.
For example, if you come from US, it usually takes about 3-5 business days to arrive your door after place the order.
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  • posted by Bill

    Device worked as advertised. Shipping was quick and simple. Installation was suprisingly easy.