Neil
Here is another way to look at it.
If you were to remove your fender all you
would have sticking out back would be
the side rails that your sissy bar is on.It
has two bolts that go through it and bolt to
the back side of the fender next to your tire.
then it also is bolted at the top mount of your shock.
The only way I was thinking about was make some kind
of plate for the IS grab rails that would fit over the bolts
that the Is trunk fits to and then have you sissy bar on that.
You will have to notch the mounting hardware on the bottom
of your trunk to allow you to remove it when you want.
Go to BigBf web site and take a look at what I am talking
about on that.
Shortleg[Dave]