Yesterday I spent an interesting afternoon chatting to Ralf Lamberti, who heads up the Mercedes' infotainment and telematics division. They've been working directly with Apple to develop a system that allows "deep connectivity" with the new A-class.
Effectively, this means that A-class drivers will have the option of paying for some wires and software as a one-cost option (likely to be around £150) when speccing the car.
This allows the phone, once fitted with the free "digital drivestyle app" to provide all the media, nav, and communication systems. You control it via a rotary switch - as you'll find in any current Mercedes - or the Apple 'Siri' voice command technology that iPhone 4S users will be familiar with.
It's all very clever. There's even an Internet radio/music library function (not dissimilar to Spotify) that comes as standard. And you don't need to pay for expensive system upgrades - the iPhone connectivity works with the base car as well as the full-fat Merc 'Comand' nav and media system.