I have driven into villages on the west coast of scotland with two dead stags tied to a quad or in an argo and never had a problem. I have also driven back 10 minutes in Dorset with dead deer tied on the back of my quad. Never had a problem. I have also in the past as a Taxidermist delivered full mounts of Lion, Leopard and Grizzly bear and never had a problem.
This clinically clean PC world we live in drives me NUTS!!

You will always get some busy body or anti who dosnt like what you are doing and takes great peasure in causing problems. If you wash your car in the street they would complain!! or moan about your wife putting kinky underwear out on the washing line on a sunday
If you are not breaking the law, and I cant see how you are by going about your legal buisness then the police should prosecute them for waisting their time.
Me......... well I am gonna carry on until someone tells me its illegal.