I know this is an old post, but found it while trying to figure out bag and fender extensions with monster ovals. I tried an experiment and it worked, I ordered standard pre painted bag extensions from Amazon (very cheap) as well as a pre painted fender extension (also very cheap). I then used a dremel and a drill mounted round sander to cut out the additional size needed for the monster ovals. I used a piece of poster board to mock a template and then used a silver sharpie to trace what needed cut on the extensions, from there I cut and trimmed with the dremel and then sanded it with the round sander on the drill. After the extensions were cut and mocked up on the bike I used Harley Vivid black touch up paint to fill in any scrapes I made with the dremel (mostly the first bag extension, when I did the second I was much better and had a lot less small flaws to deal with) and after that used black polish and buffed it out, it came out great. I did relocate the license plate to above the extension to cover the holes left after removing the fender bumper, light, and trim. I did this on a 2011 Ultra Limited and did not use any fancy license plate relocation kit, I just bent the license plate using a propane tank and drilled 2 holes in the fender (yeah that was nerve wreaking) and then was able to flex a plastic license plate frame I had and it worked just fine.

In the future I'm thinking of doing something to fill in the gap between the bag and the fender extension, not sure yet. Also, I am not mechanically inclined at all and pulled it off, here is the end result...