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.

In fact, this new function means that optioning up the expensive factory-fitted Mercedes 'Comand' is unnecessary if you're an iPhone user. Because by opting for Digital Drivestyle you get Garmin nav on your phone, plus all the audio and social networking functions you could want. And it can be fitted to the base model.

But there are some tricky questions. If you don't want to use an iPhone? Lamberti says that Merc is working on offering the same functionality with other systems, "but you have to start somewhere."

And what happens when Apple brings out a new phone that no longer connects with the system? "Nobody quite knows where smartphones will be in five years' time," said Lamberti, "but we are working with Apple weekly to keep up to date and it's likely that we'll be able to offer hardware upgrades that could go some way to solving the problem."

I think it's a great system, but also one that risks making the car feel out of date very quickly as phone tech moves on.

There is, of course, the traditional nav, USB input etc available for those who don't want such complex systems. And right now? I think I'd go for the known and traditional interfaces despite the fact that I use an iPhone and enjoy gadgets in general.