I just bought my Seat yesterday and driving on the motorway back it popped off, stupid me kept trying to use it wondering why it wasnt working.....
Got home, and found the whole of the windscreen wash was in my boot... Wasn't the nicest of surprises.
Managed to get it to clip back on, but i think i have a record amount of scratches / cuts on my hands now.
Conclusion - dont dilute your antifreeze windscreen wash : ) Much easier solution heh. Don't want to be trying to connect that again, especially not in the cold.