The warranty that came with the car covers the whole car, not just the HSV-specific parts. Talk to your dealer, who I'm sure will be both an HSV dealer and a Holden dealer, he should be able to repair the sat-nav screen and send the bill to either HSV or Holden, in this case it should be Holden.

Clearly it is frustrating, but you are doing the right thing in insisting the car be fixed. I would suggest you meet with the dealer and try and sort it out face to face rather than by phone, e-mail or any other remote means of communication. Don't be fobbed off with a junior member of staff, talk to the dealer manager. If that doesn't result in a resolution, go up the ladder to Holden and again seek to talk to a senior manager. If all else fails enlist the help of a lawyer.

I don’t believe it will increase in value in the short to medium term, in fact it will probably drop in value, but because of its relative rarity it could increase in value over the long term. If you plan to keep it in the hope it does I would use it sparingly, service it regularly, and keep it covered even when garaged.