Thanks for your replies guys.
I don't really remember even using my horn for quite some time - defiantly not the violently? Maybe I don't know my own strength!
My girlfriends +50k mile E88 badge is as perfect as the day it rolled out of the factory. She ALWAYS likes to point out fault with other road users driving abilities and uses her horn more than the indicator! haha
Spoke to the BMW aftercare to see if they can do something under warranty who said they would do a full investigation. Fingers crossed!