Thanks for all the replies chaps. There's white residue on the alloy caps, one in particular looks like acid has eaten it and parts have gone black. I've got plenty of photos of the car, a few thst show the grille to be pristine and I'm sure I've got some of the wheels somewhere too.
I said to the warranty administrator about the wheel caps and he said he would mention to the service manager. However, I only noticed the grille when I got home as the car was parked with the front facing aeay from my path of entry!
A friend who's family own a garage said it's tfr damage too, the front end looks awful now though, I've always washed carefully with snow foam, two buckets and a decent mitt.... Now it appears to have been wasted effort!
This is on top of the fact that they still haven't fixed the noise I have despite replacing a very expensive part :(