Gerritt,
Being a deer hunter myself, go throught the same reaction that you have experience today every year. For the past ten years, we've transported our animals in the back of a pickup truck without being covered with a tarp simply because we don't want the meat to heat up and go to waste.
The laws from the MNR, in my case Quebec, allows a hunter to transport any big game animal onto any vehicules as long as the proper transport coupon is attched to the animal. MNR do specify in their regulations to use better judgment as to how to transport any animal but does not in any way prevent you from displaying your catch.
We always got a mix signal reaction from people when we drove into the city, some gave us the thumbs up and some the discusting look but we don't parade for ever. Once we get to our destination, the animal is prep up for butchering just like cows and pigs and chickens etc....
Once we finish, every member of the group goes back home with meat for the freezer and part of the winter.
Like I said in the beginning, the animal is out in eyes vue for one reason only, so that the meat does not heat which would happen under a tarp.
Leechman