Bringing a car in from Canada for the show

[Canuck]

Us customs have a catagory for bringing a vehicle into the states for "show and tour" purposes for up to one year. This is assuming a car may be doing more than one show. For one show only, there is nothing required if you bring the car over the border yourself other than ensuring you have a current Canadian provincial title. You might want to check with a customs broker if the car is consigned to a carrier to leave Canada.
I took my 66 to MCACN in 2013, trailered it over the border and shipped it with Reliable from Blaine WA, Other that a few questions from the customs guy as to about was I receiving any compensation for displaying the car and if the transportation cost was paid for (no and No) by the show.
I have taken cars to Seattle shows for years with no issues.

Paul