first, modify your factory shift linkage at the bottom of the column like I did mine (see: removing the column shifter thread by me). then run the wire coming OUT of the factory NS switch (goes to starter solenoid) to the new switch that you mount on the quicksilver.
another way to do this is to run the wire coming out of the factory NS switch to a momentary contact pushbutton mounted under the edge of the dash. you would have to push this button while turning the key, so put it on the left side of steering wheel somewhere. needing to push the button will remind you to make sure it's in gear, and will also double as an anti-theft device.

oke:
Ya gotta have smart brains man!