Thanks guys for the quick responses.
Here's how the front end looks at the moment.
http://farm4.static.flickr.com/3607/358960...6fcd767.jpg?v=0
And, as you said, he gave me back two little plastic arch like things, that I don't know where it was before, or where did he take those off? Were these fitted to the front arch or the back arch? If they are for the back arch, I couldn't see any screw holes on the arch itself?
BTW, this was bought from Lexus dealer, I suppose this would be original then....
They are from the front, and this is part of your problem, they need to be fitted as they act as spacer, they use the same screws as in the pic mate, and run up the inside of the wing.
Ps, your fitter should of had a read of the fitting instructions, then they would have known, how have they fitted them to the under side of the car, just pop under and see if you can see 4 bolts (each skirt) bolting it to the under side of the car.