You probably need to be over on the Ford GT forum for the best response, but as a collector of these cars you probably already knew that.
There were 210 Canadian spec Ford GT's initially and then the last 100 cars produced went to Canada due to US laws.
I believe Canadian GT's differ in a few subtle ways;
No Macintosh option or subwoofer
A 2" spacer in the rear bumper and panel removed
Slight difference in the gauges (symbols vs. words)
Some information stickers in French & English
Font bumper gel filled to meet impact resistance standard
Headlights wired for daytime running.
Canadian GT's do seem to have a lesser value than US cars to US buyers.
I understand the car must also be built before September 1st 2006 to import to the US as a new law came into effect and it doesn't comply, hence the reason the final 100 cars produced late 2006 went to Canada.