I know it's more expensive but getting a burly tail wagon will help the odds he enjoys it. Made specifically for dogs so it's much more comfortable of a transition for them in my experiences.
At very least a Thule one designed for dogs. Amazon has a good deal on them but check your local shop if they can get it first .
https://www.amazon.ca/Thule-Courier-...d_i=B09NMMV9LQ