I'd steer away from Wonder Wheels personally but i hear it isnt as harsh as it used to be
Iron x or Envy's Iron awe will help , coupled with some decent wheel cleaner like Espuma, Bilberry or Envy's one (http://www.envyvaleting.co.uk/products-info.asp?id=358 )
My mum has a Fabia with white alloys and they are a pain but protection is the key .
I'd do , Iron Awe, then wheel cleaner , then repeat , then wash with shampoo , clay the tough bits , finally polish and then seal