you can gift him the car but he will be assessed duties and
taxes on the redbook value of the car...plus 100 ac tax and green levy if its a gas guzzler
You can have $60 taken off the vehicle value for gift exemption tariff 9816 if you write a letter stating that you give the car free of any charge to your son.
check out my site on info for importing vehicles to Canada...and other things customs related.
hope this helps.
CI