Re: rust appearing on wheel arch –
It all depends on where the rust has come from - if it's come from the underside of the paintwork, it should be covered by an/the anti corrosion warranty.
I note that it's an 06 Passat - it should be covered by the VW warranty still so you should be ok.
Go to your dealer and talk to them - nicely - and see what they say. If you don't get a satisfactory response, try a different dealer.
If you get no joy, contact VW (Milton Keynes) directly - try going to a proper paint/body shop (not one of those accident repair places) and get them to assess the damage - try to get a written report from them (even if you have to pay for it) and take that to VW/the dealers.
Audi A3 Sportback 2.0 TD SEi: Misano red, Kinetic 17s, Comfort package, Storage package, non smoking package, Nav, Upgrade to Audi sound system, Debadged