adding an amp and sub (more)

i want to add an amp and sub in my trunk....i was curious to see how the speed senstive volume control of the bose system would work for a separate sub? would the volume of the sub go up and down on the subwoofer as well, or is it impossible to add an amp and sub to the existing bose system? Thanks

and adding a high-low converter. Adding it to the existing amp will therefore adapt to the ouput so the speed sensitive volume control will work.