put one of these on today. Went fairly well. Originally i tried with out cutting as several people had posted that it is not necessary but it wasn't going to be even close to fitting on my bike. So i went back and cut, took 5 minutes with a hack saw. Afterwards it was still a really tight fit. Looked things over and saw that it was actually part of my taillight that was preventing the under tail from fitting right. So i trimmed a little off the base of the tail light and everything came together great.
^that being said i think it would have fit with out cutting the mud flap/battery plate if i would just trimmed the tail light piece.
This is definitely one of those jobs that takes you a few hours the first time but once you have completed it once you could do it again very quickly with out a single hiccup.
I like the look, my only complaint is that for the $ of these under tails i wish they put better wire on them. crap like 27gauge wire sucks. I got the smoke one for $110 and painted it black like Bob
P.S. the ll552 blinker worked fine for me as well (edit: did not work fine after riding for 30min)
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I love the smell of burning pre-mix in the morning
I don't think I'm a lot dumber than you thought that I think that I thought I was once.