i have that same exact one i ordered from dennis kirk. it works pretty good, but you gotta rig it up good or it will flop around. to make teh 7/8 fit i stuffed some paper towels in between it and it made up teh difference. has held up fine for me and you cant see the towels so its all good. i dont think i had one on my f4 either. i think previous guy took it out when he cut the undertail

 

I think mine went with the undertail too...lol

 

naw the F2/F3's never had removable seats, your correct to remove it you have to remove both the side covers on the tail... but i was almost certain the passenger peg somehow had a helmet lock incorporated into it or something

 

There just HAS to be something..........................

 

I had a F2 til the first of this year and there was a helmet lock on the left side when your sitting on it. If i remember correctly it was all part of the rear peg on that side?? If not it was right behind it.

 

Ah hah!!!!!! I KNEW it!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

I have a small hole on the back side of the left pass. peg. Kinda looks like somthing was rivited on there. Guess that got drilled off or somthing.

 

here's a pic of it, if that helps!!