I bought the whole set thinking they would work and they did not. (Flex Head) I found the other wrench I sent you worked alot better. If you look under the bike there is a bracket with a lip that faces upward towards the lower trunk area and that is what makes it difficult to remove these bolts. If that muffler bracker was flat then yes the flex head would work fine,but thats not the case.
If you had the whole back end off not problems. But since we are working around the issue this is what we had to do. I tried 1/4 sockets etc with the tight space the only way was the wrench link I sent you.