My reply from the other thread.
Picked up our Lund Pro Sport from Michigan, super simple process. Although there are a few things you need to make sure you have in order.
Seeing that Michigan is a non-title state (For anything under 20ft) you'll need to have a letter from the bank stating there are no liens on the boat(If there are liens, you won't be allowed to bring it across) RIV fee and the taxes are paid at the border (On the boat), you'll pay a bit more at the MTO when you go to plate the trailer. Very easy process, we were in and out of customs within 5 mins.
Make sure the trailer also has the inspection sticker/serial on it (Located near one of the tail lights), you'll need when registering it here.
Also make sure you declare anything over 10k in cash if going across the border.