I exported/imported my car, and while there are many many steps to the process it's relatively easy and it wasn't very expensive. luckily i did not have to make a ton of modifications to my car, so i only had to pay for the daytime running lights to get installed/turned on.
you don't have to import it the same day you land, and it can be listed on your goods to follow form as a conveyance. i would recommend splitting it up, because both are stressful enough on their own. i imported my car on my way back to canada when i went to the states for thanksgiving. that way i didn't have to worry about the 72 hour restriction. if you have something planned in the future, then it's good to consider doing it then.
there are some threads in the settlement issues board on this forum that practically give a step by step guide to how to get it done. again, lots of little steps. since my car is old and not worth much, it was significantly cheaper and easier to import my car.
people need to use a broker to initiate the export on the US side because the documentation system requires a person to be certified to use it. it's much easier to pay someone already certified to enter the information and create the documentation than going through the process of doing it yourself. all other steps to the process are done by the person importing the car, the broker can't do this for you (unless you pay $$$ money).
The car modifications aren't dealt with until AFTER the export is done and the import is initiated in canada. When the car is taken to the designated mechanic for the inspection (usually a canadian tire), the modifications will be done then. other mechanics won't have a clue about what you're talking about, and will most likely refer you to canadian tire anyway. if there's more than one designated mechanic in your area, it's best to shop around because there are some horror stories out there about having to pay $$$ for repairs. i was lucky and only paid $150 + tax.
