Hi cyberlucky,
As has been already mentioned, I went down the aftermarket Headunit way, with intergrated Bluetooth, extremely handy as the Music/GPS/DVD/Radio all cut out when there is a Phone Call in progress, I picked up the Facia from JDM Yard here in Sydney, then got a loom conversion from eBay, all plugged in perfectly with no need to cut the factory wiring loom etc.
But since you purchased the New Car, its all there for you.
If yopu are considering a cradle to hold your iPhone, try a company called Hold My Phone, they have many different holders for different places in the Jazz.