We're lost, somewhere around the back of Clevedon, without a map, when a slightly plummy female voice says, "In 600m turn right".
She's the only one with any idea which way to go, so I'm prepared to give her a try. We turn right and after a while the voice pipes up again, "In 600m, at the roundabout, take the second exit". And suddenly I realise where we are - coming up to the Manurewa on-ramp of the Southern Motorway. Saved ... by Navman.
Over Labour weekend I took the latest Navman - the iCN720 - for a bit of a drive to try her out and she performed amazingly well.
True, the only reason we were lost was that the Navman's instructions took us on an unfamiliar route, but she knew where she was going and it seemed just as quick.
But at the motorway on-ramp she let herself down by telling us to turn right at the traffic lights, which would have meant heading into the off-ramp. The actual turn was 50m further on.
But other than that it was all very quick, easy and helpful. I just used the touch-screen to enter our home address in Devonport, added the address of our bach at Kaiaua, pushed "go" and off we went.
The kit includes a bracket with which to mount the Navman on your dashboard, but it's the size of only a small book, so my wife kept it on her knees instead.
As we left home the screen showed a map of where we were, added printed directions for the first part of the route and, just to make sure, told us what to do at each intersection.
We ignored its advice to head for Lake Rd and turn right - we know it can take ages to get a gap in the traffic, but the computer quickly adjusted to that and talked us along the bypass.
After that, the Navman's route to Kaiaua was the one we usually use, mainly via the motorway, and its instructions were spot on, even providing timely advice to move to the righthand lanes of the harbour bridge.
However, just for fun we complicated things on the way home, and in defiance of the instruction to turn right out of the gate turned left and headed for Kawakawa Bay, Clevedon and Manurewa. For the first 10 minutes or so she told us grumpily to "make a U-turn at the earliest opportunity".
But then she adjusted to the fact that we wanted to take what we call the scenic route, slower than the motorway but with nice coastal and rural scenery, and led us safely home.
Apart from the blooper at the motorway entrance, and a hiccup when, for some reason, she wanted me to move into the left lanes coming back over the harbour bridge when the Devonport exit is on the right, it was a very impressive performance.
Those incidents just confirmed to me that you've got to exercise a bit of common sense in following the instructions and should not just blindly head off into, say, the Southern Alps in a thick fog because the nice lady tells you to.
If you were planning a trip around the South Island - or, for that matter, to a suburb in Auckland you weren't familiar with - there's no doubt the Navman would be a marvellous guide, and her presence might save some of the traditional domestic disputes over directions.
If you don't know the actual address you're heading for - if you were going to the Sky Tower, say, or the Auckland Museum - the Navman allows you to download pictures of famous landmarks and tell the woman navigator to take you there.
It also has a built-in camera so you can photograph places of interest - a nice restaurant, perhaps, or a great view - and add them to the in-line library.
And there's also a button to push if you want to know where the nearest petrol station is.
At present the device comes with New Zealand maps only but from early next month you'll be able to add Australia, Western Europe, Eastern Europe and North America for about $350 a time.
For anyone intending a driving holiday in, say, France the chance to have a calm voice telling you where to go - in the nicest possible way - sounds a great asset ... though at $1199 a time, it does cost more than a book of maps.