i have a 02 wrx wagon. i would like to hook up an sti intercooler sprayer from the washer tank somehow. i know i have the second pump motor for the rear window. i was wondering if there is some sort of way to rig it to do double duty? ie. be able to spray the intercooler from the i/c sprayer switch in the dash, and still be able to trigger the rear washer separately from the wiper stalk, without having them run together?