Thanks for the reply TTDegs!!
I haven't taken any photos yet as the car is covered in salt again but I'll try and get some soon. The only thing I can liken it to is sellotape. Initially I tried to rub it off but it looked like it was making it worse so I haven't gone any further with it so not really sure what's going on!
Am avoiding going to the dealers at the moment as I'm still scared from all my previous visits (plus every time it goes in for something it comes out with something else).
Was kind of hoping someone else had experienced this and that there was a fix that I could apply at little cost but it would appear not (which is good for everyone else!).