I use the game hanging syestem that goes in the receiver hitch. Just take out that one pin so once deer is in the air it will spin.
yeah I have seen those but I just dont want to have to haul it around in my bed when not in use - the idea of a boat winch makes sense though - I may check that out
I have also seen a fold up Game Rack that is mounted either in the front receiver or rear one if you have a road feeder. I had one I bought at Cabelas for around $125-150 that I put on the front of my Jeep for this reason. Left it up to serve as a brush guard to keep debris out of the radiator also.
Here is what we did for our Mules on one ranch I was on. This game carrier was made out of aluminum and could be left in the inserts on the roadfeeder or mounted on top of the Mule roof. It was lightweight. Went on quickly and put back on the roof quickly.