TPL-is right,
Buy-out requires you to give a certified cheque including pst and gst on the outstanding amount, plus generally and adim fee for safety and emission test (if required). The car could be registered to the new owner directly, who will pay you an agreed price including taxes, thus avoiding double taxation.
The more complicate part is, in Ontario pst is a must, as is with most provinces, therefore new owner will be paying the pst anyways, unless agreed price is significantly lower, there may be an issue of adjusting who pays the difference, otherwise new owner benefits paying a lower pst amount. Whereas GST is different, since gst is only charged on dealer transactions only. This maybe an issue with the buyer and become part of the haggling process.
Personally, if I were the buyer, in my mind I would not want to pay the gst, because I would consider this deal to be a private deal, whereas purchases from a dealership, may honor some repairs that happen shortly after purchase and I consider GST as an insurance premium for the benefits derive from a dealer purchase.
