Who is "everyone" and what button? Just used the site's search function and searched for all instances of the word "button" for the last 150 days. No mention I could in any way referencing some mystery button under the passenger seat.
Don
On the 2012 SERGC and probably the 2013's the passenger pillion has a threaded hole on the backside. (the side next to the fender)
When you run just the riders seat and not the passenger pillion there is a hole in the fender for the chrome plastic bolt that was under the pillion.
In that threaded hole on the backside of the pillion is a chrome (plastic) button that screws into the hole on the fender.
Running just solo you use the chrome button in the fender and the pillion bolt screws into the same hole underneath.
Running both the pillion and the riders seat you use the regular seat bolt and the chrome button stays under the pillion till you need it.
Don't make me go take a picture.
It's late.
SBB