both inside or outside possible, but for those decorative ones,
usually put outside. dun worry about tear out, coz this can't tear
out easily and cannot tear out to re-use..
here're some u can buy urself if u dun want to go to shops.
http://stores.ebay.com/EgraF-X-Graphics-for-vehicles_Windshield-Graphics_W0QQcolZ4QQdirZ1QQftidZ2QQtZkm