Just had my wings and sills repaired FOC from VW. As said, it's covered under the 12 year, so keep pushing. I think it depends on the dealer, but mine were very amicable. The cost they claim the repair totals is quite a surprise!
As said with the repair, they don't blend. I was told from various people (and the dealer bodyshop) that red is fairly easy to match - providing you've looked after the paint.. It's the metallics that are more difficult to match due to the flakes etc.
Having had the car back the panels match perfect to the doors (mine is red). The bumpers are slightly different but they always were and believe that most tornado red bumpers were a slight different shade than the metal, even from the factory.
Check that the bodyshop it's going to uses the latest technology, the VW dealer I used had 3M colour match where they use a tool to specifically match the colour of the car rather than just the paint code.
Will post some pictures up of the before/after if it helps.