If your looking to hide it, at one point I mounted mine in front of the battery on a small steel plate I bolted to the front of the frame rail. I could then just barely reach between the battery and core support through the small hole and unscrew the lid and fill with a funnel. I covered the lines with black wire covering and took a small black spray can lid and cut it to fit and put 2 small holes in the top of it and zip tied it over the nozzel in the up pipe so it looked like a sensor or something. Basically if you weren't looking for it you wouldn't see it. And the alky stayed cooler being out of the engine compartment but it was closer to the front bumper so if you had an accident....well who knows....an accident with it right in front of the turbo wouldn't be good either...
Just an idea...