Competition werkes fender eliminator, or Hotbodies. Both are over priced. I recently finished installing a hotbodies undertail. I had to fabricate plastic brackets and drill 4 mounting holes. Also, I spent nearly $100 retro fitting the LED housings with something a little more visibile/safe. I'm happy with the Hotbodies, but that's mainly because I was able to get it for $50.
I got my under tail for my sp1 on amazin and my buddy I work with got the same it has brake light with integrated turns fit was perfect normal tray mod but other than that 100% satisfied with it and the lookouts not a hot bodies I didn't like the look it gave I will have to get a picture for ya the guys we worked with for the kit had azing customer service one of the undertail a came in destroyed hit them up they overnighted us a new one and just old us to discard te other so we ended up with a extra brake light that's a win in my book.