I've been looking for a new car audio receiver so I can use my iPhone 3G in the car.

To do this there are 2 simple requirements:

1. Get sound to the speakers, so I can listen to music
2. Charge iPhone, so item 1 can happen indefinitely

My current stereo came with the car from the factory in Japan (a nice unit with 6 disc CD changer - but it's got a band expander for the FM radio). It has no AUX input so my options are using a tape adaptor + cigarette lighter style power adaptor, or a FM transmitter/power adaptor.

I've tried each method, and they both suck for quality. The tape adaptor just sounded muffled and flat, and the FM option, well, after 4 different products I still can't find one that is satisfactory.

Being in Auckland there are many commercial and low power FM stations fighting for bandwidth so it's not easy finding a clear frequency to use. And the one you find that works at home, is pretty much guaranteed to be overpowered as you drive around town. So constantly fiddling with the settings is required to keep the signal going. Not an ideal solution.

So a new receiver is the best option.

However, pretty much all the units I've tried have suffered from the same issues:

• Either they only have a AUX connector, so you need a cigarette lighter power adaptor, preferably one with a AUX out (the Kensington LiquidAUX is the only one I've found so far that works with iPhone 3G). Result: a mess of cables.

• If they have a USB connector, they might not put out enough power to charge the iPhone 3G, or if they do, they may not recognise the iPhone at all, or they recognise and charge the iPhone but the "not designed for iPhone/Airplane Mode" warning message appears.

• Or if they offer a Dock Connector, then they have the older style charging option (Firewire style charging which uses 12V and pins 19 & 20 for power, vs. USB style charging that uses 5V and pins 23 & 16), or if you're really lucky they have newer USB style charging but you get the "not designed for iPhone/Airplane Mode" warning message.

After many days of traipsing round stores, and wasted hours of actually trying to connect to different demo units, I'd given up the search. I'd resorted to using earphones and only doing short trips between recharging my phone.

But then I heard that Alpine had released a new series of iPhone 3G compatible car audio receivers. These receivers connect to the iPhone 3G via a dock connector, support USB charging and most importantly, do not give that annoying message about "this accessory is not designed to work with iPhone 3G" and the suggestion to try Airplane Mode.

The new receivers are digital media only (plus AM/FM radio), so no CD player, just a dock connector and a lovely front panel display for controlling your iPod/iPhone (or other generic USB MP3 player).

The iDA-X305 is the top of the line beast, and has been available in Australia for a couple of months.

To find out when the X305 will be available in NZ, I contacted the New Zealand distributor for Alpine products. Their response was basically 'not for some time, as they still have reasonable stock of the old model [iDA-X001]'. Which is just superb, since it's one of those products that falls into the 'Dock Connector/Airplane Mode warning' group.

Now, with only the iPhone 3G officially available in NZ (the iPhone was only available by grey market importing), the chances of selling the older X001 aren't very high. And rather than get in some of the new model and sell both items side by side (well let's be realistic, the old model would just sit on the shelf while the new ones got sold), they'd rather just keep the old ones sitting on the shelf, and persuade (force) customers to buy a different brand.

Way to go guys!