I haven't mastered the digitial camera yet.
I will try to elaborate. The location is the black plastic seatpan, the most rearward bubble (for the helmet). I just used the Harbor Freight $10 angle grinder and cut out the entire bubble. Note: when using a grinder (can't use a saw blade which cuts) it grinds/cuts continuously so there is a little issue with the plastic heating and re-glueing itself together. I used hvac foil tape ( much better than duct tape) and depressed the hump while applying the tape to allow the foam to move downwards when sitting on the hump. You may not want to cut out the entire bubble, instead cut out two half moon shapes with a 2-3" verticle (long axis of scooter) length of plastic as a support then you won't need to tape it. IMO, butt stops/pads are non-functional and annoying, builders should keep the seat smooth from front to back, if needed then install a real backrest.