If it's hitting the outside section look behind the fender liner and see if where the clips are, if there are metal tabs that it clips to. On the 8th gen there were metal tabs holding the liner in place. You could roll/bend the tab flat and tuck the liner behind it. Usually you didn't have to roll the whole lip, just the tabs and it would give you enough room. The liner was tight but just do the bend incrementally.
I haven't had a chance to look behind the liner of a 9th gen yet so it could be different. Worth a try though since it will save you rolling the whole thing and possibly get to keep the liner.
I went with 18x9s on my 2012 si. I got my fenders rolled with a slight pull, the back fit perfect as did the front. But when I hit a bump or when I drive up a drive way it rubs in the middle of the plastic in my fender wells. (Just front not rear.) I want to find a solution besides getting front camber
