i have had the best luck with "3M glass cleaner". i use a blue surgical huck towel (lint free) to clean them... in the pattern of: side to side, up and down, side to side and around the perimeter to finish... flipping the towel as i go...to a streak free shine.

glass cleaner: http://shop.store.yahoo.com/yhst-691...828/mmm89.html

surgical huck towels: http://www.eriecotton.com/Surgical-Huck-Towels-c-74


~ best tip... do not wash your windows in the direct sunlight. (='s smears/streaks) ... (fyi - windex is the worst glass cleaner for car windows).