I went through the same thing when I moved from Canada to DC. KTMs have labels for EPA and fmvss in addition to the Canadian labels for environment Canada and cmvss. The fuckers at KTM were completely unhelpful and never pointed out the bikes had both labels. I just noticed them by happenstance when I was cleaning the bike up before putting it in the moving truck. Since those labels are on it, no need for any letters. My BMW GSWC on the other hand is a huge ordeal. BMW Canada and USA were unwilling to give a letter. I was able to temporarily import since I'm here on a temp basis but man, what a bunch of BS. Makes you wonder what would happen if you fired up a word processor and write a letter yourself.