The answer to either of those is yes, you do
not have to change the tail or plate light. However, the plate light is a tight fit so you have to use a little pressure to get it in there but it works fine. I did not have to cut any wiring or use different connectors and I too bought an ABS project box (2"X4") and used the rear-set bolt holes to mount it. This means that I'd have to move the box if I want to put the bags on because I have the Tail Tidy in the lower position, but I don't really use the bags much. I did have to file out most of the holes a little because things didn't quite fit right but it was an easy fix. Also, depending on where you live, the license plate mounting holes are set up for UK plates so you'll have to drill a couple of new holes in your plate to get them on. Overall, it looks so much better than the stock mud-flap that comes on the bike.
