Not so much "what I did to my GTI", more "what some twonk did to my GTI in Waitrose car park"...
We are not amused.
It’s so annoying when that happens, and more often than not, the perpetrator doesn’t take responsibility for their actions 
On a positive note, it doesn’t look as if the paint has been damaged, and being the front wheel arch, it’s easy to gain access to the inside of the panel once the wheel arch liner’s been removed. So, a good paintless dent removal operative should be able to sort that out quickly and easily at a reasonable cost.
Thanks for the sympathetic responses. It's immensely frustrating, and of course there was nobody around when I got back to the car (which, as always, was in the furthest corner of the car park), bearing in mind that this was Lymington, the average inhabitant's age being 80+. I was chatting to the owner of one of the shops in the High Street, a keen biker, ex BSB racer, who often rides to work and parks his bike in a "Motorcycles only" parking bay opposite his shop. He stood in his shop one day, and watched some old Doris reverse into his bike, knock it over, and drive off blissfully unaware.
A local dent removal company, which I have used before for another car park dent, has been contacted.
