that rear window nozzle spraying water all over except where it's supposed to go sounds like a classic case of misalignment. Luckily, adjusting it should be a piece of cake. Most rear window nozzles can be adjusted by using a pin or a needle to carefully direct the spray where it needs to be. Try gently nudging it in the direction you want it to go. If that doesn't do the trick, you might need to pop the nozzle cover off for a closer look or even adjust the hose behind it. Just take it slow and easy to avoid breaking anything.