You should have done an Inno fairing... They work with oem cross bars. I got one for me Legacy and it actually works quite well. This mighty mounts used to come with some inserts to make the mount fit better on some bars, but they won't fill the gap the size that you have. There are actually two sizes of mighty mounts for oem bars... You must have the bigger ones. The smaller ones might work better for yours? Should be the mighty mounts for the 02-07 wrx wagon rails. I think I might have a set sitting around if you're interested or want to test fit. I've battled with rack fitment plenty of times in the past, so I feel your pain lol. Otherwise, worst/last case would be the new Yakima universal mighty mounts. I haven't experimented with them yet and they look a hair large, but they might work.