The MudSling GS_LC for the 2013~14 R1200GS/ADV fits BMW’s stock side cases and most, but not all, aftermarket pannier mounts. It fits Touratech Zega Pro, Jesse, and SW Motech. It does not fit with Hepco Becker mounts.
Avant_LC fits the standard GS with either BMW’s standard or optional Enduro skid plates.
Avant_LC also fits the 2014 GS/A with BMW’s standard skid plate, but DOES NOT fit GS/A with the optional Enduro Skid Plate part #77148533747. To enable longer suspension travel, front end caster angle was changed on the ADV, reducing clearance with the Enduro plate.