One point on ice you buy from the store. Stay away from cubed ice and buy the solid blocks. It only took me three years to figure this out.

I brought three antelope 700 miles in my little Geo Metro one year in 80 degree weather. I had them quartered and wrapped up in a holey space blanket, surrounded with about 10 bags of cubed ice. The meat was just fine, but the ice melted and carried bloody ice water all over my car. I had it in the floor mats behind my seat, down in the spare tire well, just everywhere. Three years later my car still smells gamey on a wet day! Not a great rig for picking up little miss nail polish and hair mousse, I'll say that.

Anyway, the solid blocks melt much more slowly.