The ease of being able to reach back and turn the bottle on would be better for me. I have seen people use blankets or cut the bottom out of a cooler to hide the bottle itself. I usually throw a blanket over my bottle in the trunk, just to help keep it warmer and help keep it from being damaged should anything in the trunk shift on a hard corner.
Sorry this is off topic, but Ive been looking for those radiator hoses and cant find them anywhere, where did you get those?