There are also some different regulations on importing cars, im not sure if the 15 year rule is relevant to american cars, but i think it might be, i know for example that importing an EVO is illegal.
Check out
www.riv.ca is a major site , but some things may be confusing for the average joe.
or see
http://www.riv.ca/english/US_vehicle_admissibility.pdf
Hope that helps you a bit, its a hassle but i love my car and am glad i had it imported, plus its cool being different, not that you will be with a jetta. (Ps my car came from Japan not the US)