My Basenji has always hated wearing a coat (and harness) and as we are in the UK without very extreme temperatures, we stopped pushing it and she manages fine without one. If she gets rained on it a good way of getting her bathed!
She also used to run away from the collar, but we solved that by placing a small piece of chicken on the front door handle and she now sits nicely waiting for her reward!
Have you watched how your parents put it on to see if they are doing anything differently?
Some people have success with gradual desensitisation and using rewards e.g start with putting it on the floor and placing a treat on it, then when he goes to sniff the treat, say "coat" and treat him again; then move onto touching his back with the coat briefly and treating again, moving through the different stages of putting on the coat until he is comfortable - it can take a while but might be worth a try.