We used to hunt of motor cycles and used a gun scabbard on from forks or buck horns across handle bars. Packing a deer out was across the rear rack tied tight or debone into pack. We never hid our guns and I even pout a scabbard on side of my Harley with I rode 300 kms to purchase a used gun. I did get stopped by a cop at 7 am as it was not during hunting season and he asked what i was doing, he said it just seemed so odd yet not illegal, he just wanted to clarify, which I was fine with. If the shotgun on back of seat drew heat did he leave his vehicle to go in and pay or use the can, then it has to be out of sight or covered when unattended