I usually mount the pump right below the tank and if you putting it in the cubby on the drivers side there should be room below the tank there for the pump...

 

But I heard that the pump can be right next to the tank (it doesn't have to be below the tank). These pumps are strong enough to pull it.

 

^It's better for efficiency I would think. The harder the pump works the shorter the life span. Just a thought.

 

IMO keeping the tank and the pump near each other keeps the related work area to install in one clean tidy area.

The Shurflo pumps can be installed higher then the supply, buts its the initial prime of the system that could be a pain. Keeping the pump inlet slightly below the tank outlet (or more) makes priming for initial use after an empty tank more fool proof.

Personally I like the pump next to the tank (one side or the other) with the pump inlet facing the bottom of the tank.

If you can keep looking you will find some nice ideas via images of other installs on here. If you pick a unique spot post up images to share so others can see and get ideas.

 

If you mount the shurflo pump higher up then the tank you should also make a purge button for it so you can purge the pump just incase it looses its prime just in good business