Hi - as far as I understand it is not require to fix your car prior to landing.  You can fo it after import within a certain time-frame. I'm sure you can do it fixes before landing as I'm sure there are plenty of other things on your mind after landing - would be nice to have the car taken care of. I'm sure you still have to have the car inspected in Canada though? Re insurance, I did some research as I am in the same situation and I understand I can get Canada insurance once the car is imported. 
Info about importing  http://www.riv.ca
Info about exporting (from US)  http://www.cbp.gov