Help with a decision. With a top box or without?

I like the back pad idea. Need to make it a slightly wrap around type style.

I like the w/out look too. Make it quick release and have the best of both !!
 
I think you should go find the whale fin off something like a Fiero GT and stick in on there instead of the nose cone. I see you're on the other side of the pond so maybe off a Porsche verses the Pontiac.