I did explore the vertical mount concept but it blocks the already limited view to the rear. For stability and good anchorage (in case I am in an accident) I opted for horizontal with dual 1/4" aluminum brackets, 4 good sized bolts and double washers. It's not going to go flying around the inside after an impact. Also I just like the sporty look and aesthetic symmetry of the tire mounted this way. And, I can unmount the tire and remove the tire mount from the floor in about 2 minutes.