You know if you are amplifying the fronts then you will need the GMRC 01 because that one has the speaker built into it, where the GMRC 02 uses the driver side speaker. The guy above is right the one you got is usually used for onstar applications but can still be used if you don't want to here the chimes.
http://www.amdistributors.com/mobile...PP%20GUIDE.pdf
..looks like a choice of GMRC-01, GMRC-02, GMOS-01,GMOS-04
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