Steps to import car to Canada

I'm a Canadian citizen that has been living/working in the U.S. for 5 years. I purchased a vehicle in the U.S. and am now looking to move back to Canada and bring my vehicle with me. From my understanding this is the process:

• Find a U.S. agent (e.g. AutoExports.us, Freight Forwarder, Broker etc.) to electronically file my vehicle export information to AES, which will provide me with an ITN
  • Is this required? This was the step outlined by riv.ca, but it seems like plenty of people on this sub have successfully done it themselves?
• Send ITN and title to CBP at least 72h before crossing
• Complete Form 1 from RIV/CBSA at the border
  • Can alternatively email them a copy in advance
  • Pay registration fee, GST based on redbook value of car (is this self-declared?), and A/C environment fee
• Complete B4 (BSF186) for exemption up to $10k at the border
• RIV inspection at Canadian Tire
• Bring Form 1 and B15 form to MTO and pay PST and get registration

Am I missing anything?

Additionally, I'm currently already in Canada along with my vehicle just visiting. From my understanding the vehicle must be on U.S. soil to complete the AES/ITN process. Does this mean I should plan to return to the states for several days to complete this process before driving back to Canada again?