Why do you need it 'vertical'? Is it an OCD thing?
I mounted mine to the box in my bed and it works out great back there. I wanted to get it out of the way and get the noise as far away from me as possible. If I didn't have the box I would have mounted it right to the bed in the same spot. I just unplug it and pull the hoses off to remove the box. Mine's a Rugged but it's pretty much the same