I've got a Yakima Load Warrior with a full size spare. There is a wind fairing on the front of the rack, but I'm sure that this setup has to have an effect on my gas mileage. I'm considering getting a tow hitch with tire mount, and possibly having a new fairing designed. This setup would also have the added advantage of allowing me into more parking garages, as my current setup has me at about 7'. Most parking garage are about 6'8", which is just barely enough room for a lifted VX with the Yakima Load Warrior.

My questions:

How much aerodynamic benefit would I get from a) moving the full size spare to a rear tow hitch mount and b) designing a new fairing for the Yakima Load Warrior. Would it significantly improve gas mileage or acceleration?

Has anyone seen a rear tow hitch mount for a full size spare that would allow the rear door to open without removing the spare?