Hi guys! I'm new here and thought I might help out with the mounting of the factory panniers and bags for the GRiSO.
I just received mine from Erico Motorsports in Denver. Not necessarily a plug (nice bunch none the less), they just happen to be my local dealer.
In the box will come a left and right side pannier, two bags, and a bag of fasteners. Mine included instructions on how to mount the bags on the panniers but no instructions regarding the mounting of the panniers. Not to worry. I hope this helps:
Remove the four spool-like pieces from under the seat pan. There are two on each side. In the fastener bag there will be four identical hex-head screws. These will be used to mount the top horizontal portions of the pannier to the GRiSO and are inserted through the eyelets into the bottom of the seat pan. Thread in the screws loosely. The somewhat vertical strut portion of the pannier should be pointing toward the front of the bike. On the inside of the passenger foot rest bracket is a threaded hole to mount the vertical portion of the pannier. This is where it becomes somewhat interesting: there are two screws and a sleeve and one might wonder about which goes where. The longer screw which is 50mm (2") in length is for the left pannier, the shorter screw is for the right. The sleeve is useless so don't pay any attention to it. Here's why: with or without the sleeve, the lower pannier mount will bind on the back of the passenger footrest bracket. My solution was to obtain a stack of washers which I obtained at AAA Metric, a fastener store in Denver. Needless to say, you can use any source. My washers were approximately 1/16" thick and I made a stack of approximately 7/8" and placed them between the flange of the pannier support and the back of the passenger footrest bracket and tightened the provided bolt. Lastly I tightened the hex-head screws for the upper portion of the pannier mounts.
Moving to the right side of the GRiSO, I used the shorter bolt that came with the fasteners although I had bought another 50mm bolt. Well the 50mm bolt can not be used because of the arm atop the drive shaft-CARC assembly. One must use a shorter bolt. Rather than return to AAA Metrics for a 40mm bolt, I simply used the bolt provided and made a stack of washers of approximately 1/2" and then tightened the lower mount followed by the upper mounts.
The bags are pretty nicely constructed although unlocking the bags from the panniers is done with the key inside the bags. The push button release is easy and straight forward.
There are other bags out there, some might be better, some worse I suspect. These suit my needs. I hope this information is helpful!